Good Job! Homework #7 Done!
About Question #3:
In this case, you decided to bet out yourself and two players behind you go all-in. You would have to invest $8.40 in order to participate in a $22 pot, which corresponds to an equity of 27.63%.
Board: Q:h 3:s 2:h
Dead:
Equity Win DrawLoss Hand
Player 1: 38.538% 38.538% 0.000% 61.462% 5h4h
Player 2: 14.540% 14.540% 0.000% 85.460% QQ+
Player 3: 46.921% 46.921% 0.000% 53.079% 22-33
You get the required odds even when you're exclusively up against very strong hands!
About Question #4:
Top pair / top kicker has been and will always be a hand that's tough to play, especially in a multi-way pot. In this case, you've hit a nice flop, but you're up against 3 opponents on a dry board which doesn't allow for any dangerous draws.
A fold on this board is, of course, too weak. You can't really hit much better and there might be worse Ax hands willing to pay you off.
If you think that your opponent(s) is/are often willing to go broke on the flop with worse hands, raising might not be the worst of choices. But one thing is clear: if you raise, you have to go all-in on the flop! Raise/fold with your top pair is absolutely out of question.
Even though this might leave a bitter aftertaste in a 4-way pot, you should play this like a way ahead / way behind spot here - by playing it passive, you will extract the maximum from weaker hands and bluffs while avoiding big losses against stronger hands.
Best of Luck on the Tables.