FR / SnG Player looking for HU advice.

Basically my only HU experience is end of tourney, which is almost always short stacked to a degree. I feel pretty good about my ability to adjust to villains at that stage of the game where it's push/fold or slightly deeper, but deep-stack I'm a little out in the dark.

I read the HU digest, then tried playing some 50NL HU (I'm a 50NL FR reg). Are the BR guidelines the same for HU as they are for FR?

I felt ok preflop, opening my 3-betting range, adjusting to villain's preflop aggression. What's a 'standard' 4-betting range for most HU players? Is slowplaying KK+ standard preflop?

I was playing this one villain who was very aggressive post-flop. Constantly c-betting, and when I tried to push back, he'd float & bet more where I'd have to let my air go. I felt like he was steamrolling me, but I didn't have the cards to fight back. I guess I should have just been more patient? When I finally got a hand (trips on a 3-flush board), we went in and he had a boat. I'm not experienced enough to know whether or not I played it correctly, so is there some general guidelines as how to play post-flop or is it all villain dependent?

What kind of hands are most villains willing to go broke with on the flop? TPTK? TPNK? What hands (with no read) should I be more than willing to go broke with?

Sorry for the post being all over the place, any answers to any of the questions I posed would be much appreciated, or even just a link to post-flop HU play would be much appreciated.