Hello, I'm playing 6dollar HU turbo on FTP and got couple of questions :)

1) how do you deal with donkbets? I will give examples

-Blinds 15/30- you raise button with AJo to 60, BB calls
(Pot 120), BB donkbets 60 or 90 on a 78K or 258 board, what do you usually do? I guess it depends on the opponent but its hard to tell when its 5th hand between us for example

or same thing, you open with 89, flop comes T83 and he donkbets. Do you just call?

2) open Button raise? I have been making it 2x always regardless of blinds. Should I be making it 2,5x or 3x when the blinds are small?

3) c-bet? When pot is 120, how much is it best to c-bet, i usually bet 60 which seems to work, occasionally bet 90 or so depending on the flop. But I usually bet 60 when I miss and the flop seems ok to bluff at vs. my opponent

4) My stats VPIP 48, PFR 37, AF 2,2, 3Bet 18, fold to 3Bet 48 (12K hands)
If anything should be higher or lower, let me know. I know everybody has different style, still reaction would be apreciated

I have a ROI of 11,6% over 400games sample of 6dollarHU, still I would like to sustain it or make it higher... so thanks for the answers