I'm trying to do that, as best I can, but, since Fel is playing deck with blue in it, we still need to keep the stack, in case of instants.
But, generally, if there's nothing that can be done (assuming Fel passes priority back and lets the Kor resolve), we'll skip the rest of the phases, and move to his upkeep/draw.

I'll let the pesky kor resolve.

OK - Kor has resolved, True already let me know he's passing for the rest of the turn.
Fel - any actions on end step, or are you ready to draw?

Edit: Fel has completed draw on T2.
Action is on Fel for First Main Step
(board in post 1 is updated)

MP1 Island, pass the turn.

Is that passing through till end of your end step? Since we know True is tapped, and has no 0 mana instants...

edit - board is updated, True has untapped, and has drawn a card.

Action is on you, True!

Well, I think "pass the turn" is very clear. Yes, I'm passing through till the end of my end step.

Just trying to be extra careful! This is my first time

Ok. I play a third Plain and other Kor Spiritdancer. Pass.

Just to clarify, we can respond in these phases:

End of main phase 1.
Declare attackers step.
Declare blockers step.
End of main phase 2.

Or Im missing something.

And, as an interrupt whenever someone casts a spell.

Kor is on the stack!

Fel - priority is on you.

I tap 2 Islands and cast Counterspell, targeting the Spiritdancer.

I do nothing and wait for my next turn.

True's 3rd turn ends. OP is updated with current board state.
Fel - you are drawing a card for your 3rd turn

MP1 Island, go!

Pass till end of turn, or do you have a MP2 play?

Pass the turn

Card draw sent to True.
True - your turn, Main #1

I play a plain and Armored Asconsion targeting my Kor spiritdancer. Pass and I want a new card.

Armored Ascension is on the stack.
Kor triggers a card draw, which is on it's way.

Tap 2 Islands, cast Counterspell targeting the Ascension.

Neosilk. The right way would be to put the card draw on the stack. There are cards that could counter the kor wability.