So what is exactly happening here is you are casting a creature and your opponent must Counterspell that creature in order to get access to the Pool before you.
The current stack is
Opponent's Pool Trigger, Counterspell, Your Pool Trigger, creature.
This then becomes
Opponent's Mystical Tutor, Your Pool Trigger, creature.
The Mystical Tutor will resolve before your pool trigger in this case.
Knowledge Pool also does count as casting two spells.
This is correct. When Lilly resolves, you will get priority with BBE on the stack. You need to pass priority and an opponent needs to pass back for BBE to resolve. If they kill it then, you'll be left without an opportunity to use Lilly.
They are all going to resolve individually and you will get 3 separate 1 damage triggers. It will die with the last Pestilence activation on the stack.
Combat damage happens and here is the relevant parts of the game state before anything happens;
Blood Artist with 1 damage marked, one player at 1, one player at -4. At this point, state based effects are checked, Blood Artist dies at the same time as the player losing the game. Artist's trigger will never actually go on the stack.
When asking rules questions, it helps a lot if you only include the cards that actually matter as it'll save people the time of trying to figure out what cards a relevant here. It looks to me that the question being asked is will you still take Kaervek damage if you are flashing in a creature via Canyons. You will still take the damage in this case and will not be able to go off indefinitely. Let us know if this is not actually what you're intending to ask.
The hardest part of the deck is understanding the mana base but it's definitely a fine call right now and a top tier deck. I know, for instance, it just top8ed the MTGO PTQ and the one in Philly. Aggro is huge right now and the deck has a lot of anti creature tools but can be adapted to any meta.
Unless, like you mentioned, you make Reckoner indestructible, it's going to die to the first burn spell and be placed in the graveyard before the second spell resolves.
I wanted to expand on some stuff but also included anything weird I could think of from the format's top decks.
Tarmogoyf doesn't die to burn if the spell in question will level him up enough so it's not lethal. EX: Lightning Bolt a 2/3 (creature land) Goyf. It becomes a 3/4 with 3 damage.
Legendary lands die without using the stack. If you try to Legend rule an opposing Eiganjo Castle, your opponent cannot float mana.
Spellskite can stop any Deceiver Exarch/Pestermite + Splinter Twin/Kiki-Jiki combination EXCEPT Exarch + Kiki-Jiki. This is because Kiki can only target your own creatures and Deceiver is modal targeting your own creatures and Spellskite cannot change modes.
Spellskite can always be activated to recude your life total even if it can't change the target (ex; Divination). This is relivant for Mindslaver and and Death's Shadow.
If Phantasmal Image is targeted by a removal spell, Spellskite cannot save it.
Linvala, Keeper of Secrets stops all activated abilities of opposing creatures, including mana abilities like Birds of Paradise.
Deathrite Shaman's fist ability is not a mana ability and can thus be responded to. Removing the target for this (or any of his abilities), will counter it.
I will word this specially but feel free to extrapolate this; if Electrolyze targets a creature/player and Spellskite, you may not redirect the 2nd point to Spellskite as it's already a target or that part of the spell. If Martial Glory is +3/+0ing Spellskite and 0/+3ing another creature, you may redirect the 2nd half to it. The difference in these two spells is that one calls for separate targets.
+1/+1 counters and -1/-1 counters cancel out. Persist creatures may persist again.
You can always find a smaller creature than you search for with Chord of Calling.
You counter Suspended spells when they come off of Suspend- not before then.
Valakut works if Mountains enter simultaneously including the 6th Mountain. Some decks will have 5 & 6 enter at once, resulting in 2 triggers per Valakut. Some will have all 6 enter via Scapeshift. This will result in 6 triggers per Valakut.
Vendillion Clique can target both players and doesn't need to take a card.
Players may crack a fetchland between Delver triggers and after Delver but before the draw step.
Body Double copying a Reveilark in the graveyard can return itself since it will have 0 power in the bin. You can combo various ways by continuing to copy the Lark.
I'm not entirely sure of the exact make of the deck I want to make but I know the shell starts with Green and can easily support another color. The main synergy is Devoted Druid, Lotus Cobra, and 5s- Primal Command, Plow Under, Garruk, Sword of W&P/F&F, Batterskull. You would probably want Birds/Noble/Deathrite to make yourself more resilient to spot removal but the goal is just to cast 5-mana spells that can beat certain decks heads up. You board out the bad ones and just aim to always have the best end-game with your disruptive 5 drops.
I've always thought a neat addition to the game would be to allow sideboards to have 1/4 (rounded up) # of the cards in deck. This would mean playing a 61st card would give you access to another card in board and would create an interesting dynamic. However, the current sideboarding rules require your sideboard to always be 15, thus elegantly also reinforcing that you need to board in and out the same number always. If we saw a legitimate change it wouldn't be to 18 most likely since it's not a multiple of 5 and 20 is probably too many. A variable sideboard that I mentioned is probably bad for a number of reasons too.
1. It's considered that for invisible triggers that have no affect on the board state that they are considered to have triggered unless you demonstrate not being aware of the trigger. Both of Thragtusk's abilities however, effect the visible board state (which includes life totals) and need to be announced the moment they would happen. What you don't need to announce are things like Exalted. This is an okay exchange. "Swing with Qasali Pridemage." "No blocks. I take 2." "No you take 3."
2. Correct. You don't have to Trample however it's assumed that you do if you don't say anything to the contrary.
The current stack is
Opponent's Pool Trigger, Counterspell, Your Pool Trigger, creature.
This then becomes
Opponent's Mystical Tutor, Your Pool Trigger, creature.
The Mystical Tutor will resolve before your pool trigger in this case.
Knowledge Pool also does count as casting two spells.
Blood Artist with 1 damage marked, one player at 1, one player at -4. At this point, state based effects are checked, Blood Artist dies at the same time as the player losing the game. Artist's trigger will never actually go on the stack.
Winding Canyons
When asking rules questions, it helps a lot if you only include the cards that actually matter as it'll save people the time of trying to figure out what cards a relevant here. It looks to me that the question being asked is will you still take Kaervek damage if you are flashing in a creature via Canyons. You will still take the damage in this case and will not be able to go off indefinitely. Let us know if this is not actually what you're intending to ask.
Tarmogoyf doesn't die to burn if the spell in question will level him up enough so it's not lethal. EX: Lightning Bolt a 2/3 (creature land) Goyf. It becomes a 3/4 with 3 damage.
Legendary lands die without using the stack. If you try to Legend rule an opposing Eiganjo Castle, your opponent cannot float mana.
Spellskite can stop any Deceiver Exarch/Pestermite + Splinter Twin/Kiki-Jiki combination EXCEPT Exarch + Kiki-Jiki. This is because Kiki can only target your own creatures and Deceiver is modal targeting your own creatures and Spellskite cannot change modes.
Spellskite can always be activated to recude your life total even if it can't change the target (ex; Divination). This is relivant for Mindslaver and and Death's Shadow.
If Phantasmal Image is targeted by a removal spell, Spellskite cannot save it.
Verdant Catacombs and Misty Rainforest can fetch Dryad Arbor.
Linvala, Keeper of Secrets stops all activated abilities of opposing creatures, including mana abilities like Birds of Paradise.
Deathrite Shaman's fist ability is not a mana ability and can thus be responded to. Removing the target for this (or any of his abilities), will counter it.
I will word this specially but feel free to extrapolate this; if Electrolyze targets a creature/player and Spellskite, you may not redirect the 2nd point to Spellskite as it's already a target or that part of the spell. If Martial Glory is +3/+0ing Spellskite and 0/+3ing another creature, you may redirect the 2nd half to it. The difference in these two spells is that one calls for separate targets.
With Haakon in play, you may cast Nameless Inversion from your yard.
+1/+1 counters and -1/-1 counters cancel out. Persist creatures may persist again.
You can always find a smaller creature than you search for with Chord of Calling.
You counter Suspended spells when they come off of Suspend- not before then.
Valakut works if Mountains enter simultaneously including the 6th Mountain. Some decks will have 5 & 6 enter at once, resulting in 2 triggers per Valakut. Some will have all 6 enter via Scapeshift. This will result in 6 triggers per Valakut.
Vendillion Clique can target both players and doesn't need to take a card.
Players may crack a fetchland between Delver triggers and after Delver but before the draw step.
You must take a card with Thoughtseize if possible, even if their only card is Obstinate Baloth.
Body Double copying a Reveilark in the graveyard can return itself since it will have 0 power in the bin. You can combo various ways by continuing to copy the Lark.
Sun Titan can return Enchant Creatures and attach them to hexproof/shrouded creatures.
2. Correct. You don't have to Trample however it's assumed that you do if you don't say anything to the contrary.