1: Fold pre-flop.
Depending on my villain's stack(s), I don't always throw this hand away. I recently won a $700 pot with 24o because the other two in the hand were stacked deep and my hand was hidden. CO raises to $15 pre, SB calls, I call. Flop comes Q72, SB bets $25, I call, CO calls. Turn comes 4, SB bets $100, I raise all-in for the rest of my $300 stack, CO folds, SB calls, fails to improve his AQ (CO had AQ too.) Perhaps over the long run it's -EV to put $15 in with 24o PRE, and another $25 in with only bottom pair no kicker, but when I improve to two pair and my calling range isn't expected to have a 2 or a 4 in it, I get some value added by playing sneaky cards.
2: If you do somehow get to the flop, check-fold.
Agreed entirely. Depending on the flop I may as well just fold. For instance I have 76s the same flop comes out and I'm not hearts. Easy fold.
Runner-runner trips, maybe just a random 3 or 4 will beat a Kx or Qx.
4 high doesn't have much value but it has some value which is better than none.
Again, I sometimes play these hands (in cash games only) for their hidden value. If I whiff and can get away for cheap, that's fine. Against a deep stack I like to play a lot of hands and hope to outdraw them. When done with caution it can pay off.
By staying in the hand you risk spewing chips by calling a bet when you catch a pair or bluffing in a bad spot. Whilst you should only be putting those extra chips in when it's proffitable, you could simply make a conscious decision not to put any more chips in and immediately show a proffit over folding.