Obv gameflow dependent but here are some of my opinions (Assuming freezout tournament, so not Turbo, sattelite or bounty and standard payout structure, assuming 2-2.5x opens):

1-  A stack size I'm not too sure about is the 25-35bb region. What is my flatting range against aggressive players in late position who are raising a lot of hands in this spot?? And is 30bbs too much to just 3bet shove Small Ax's.

Assuming you mean flatting from the Blinds so OOP:

I would Flat 55-TT TJo-KQo, T9s-KQs.  I would play flop aggresively (so check-raise most made hands and some air)

I would not be shoving Ax this deep, I would wait until I am 20 or less bbs at least  

2-  I'm in late position with small A2-A6 with two aggressive players in the big blind both with 20-30 bbs.. I expect them to 3bet jam wide in this spot as I myself have an aggressive image and they still have a lot of fold equity, however obviously A2-A6 doesn't play great against any sort of 3bet shoving range….so is it better to just open fold here???

Assuming I have about the same stack as they do, I shove a good portion of the time if closer to 20 bbs and fold when closer to 30.  I wouldnt open this.

3-   First hand of a MTT 150-200 BB's deep, what is your opening range? ATM I pretty much open any pair just because I figure I've still got the implied odds with small PP's even if I get 3bet.

UTG or on the Button?

UTG: any suited ace, any pair, TJs+ KQo

Button open: Any suited Ace, any pair 98o+, 56s+ 46s+