Good Job! Homework #5 Done!
Seems like you are running really good and playing good pokah.
About Task #3
It's a very close decision: does protection or pot control weigh heavier here? Do you want to protect against hands like 3x or A:dx and K:dx? Or do you want to control the pot size and try to induce a bluff on the river in case there is no T, no J and no additional

?
Raise/fold is out of question - with the given pot size and the good made hand you have, it can't even be considered.
In case you decide to go broke, you can't really be blamed either. It's not a sign of weakness that the rather tight small blind decides to bet into two people here, though. I would say a call is to be slightly favored, while the many outs against you are annoying. The big blind who calls rather loosely speaks in favor of a raise/broke again. Both options are finally considered equal, which shows - all things considered - how close and full of variance these spots really are.
About Task #4
You've called pre-flop and then hit a good board. You basically have two choices now: either you assume that your opponent will go broke loosely or puts you on a bluff often and you thus check/raise - or you play check/call in the spirit of way ahead / way behind. The problem with the latter is that there are a lot of cards you don't want to see in the later course of the hand. All in all, it depends on your balancing as both lines make sense under certain circumstances.
A check/fold would be really pointless, of course. It's hard to say whether you should donk-bet here; donk/fold can be discarded as that would turn your hand into a pure bluff and your opponent would interpret this as weakness and start raising you out of flops with hands like AK/AQ/air. So, if you want to donk-bet, it has to be a donk/3-bet.
Good luck on tables and with the Course.