Without checking the exact wordings wouldn't Adar on Yavaris allow 4 attacks of one squadron.....yavaris activates squadron for two attacks, adar flips its activation slider back, yavaris activates it again for two more attacks.
Basically if adar kicks in immediately after the squadrons activation it should work, if he takes effect at the end of the ships activation he wouldn't.
I agree with the four attacks, Since you are supposed to activate the squadrons one at a time
Nope, you re-activate the squadron after the squadron command has finished resolving.