Good Job! Homework #8 Done!
About Question #3:
In this case, the right answer is quite obvious. Both AF and WTS speak in favor of a check behind for bluff induce. But your hand is too strong here, so you want to get it all-in on the turn. There are a lot of hands you still have to protect against, too. Playing for bluff induce or pot control would simply be too weak and dangerous.
About Question #4:
About preflop play I'd say that it's still doable while we even are a bit deeper. I expect the hero to play solid postflop play. So Calling is definitely fine here with having 2 opponents in the hand and getting great implied odds. But for more beginners it's deifnitely a very close spot while they ain't gonna be able to laydown weak hands.
As we have the information that CO is a TAG player. Therefore, we expect him to have a strong 3bet range. Unless we have some other information like he has a wide 3bet range. But while we don’t have that, we basically consider his range to be something QQ+, AK or sometimes even tighter.
So now you have to ask yourself what kind of hands would play like this on river? KK may slowplay like this. QQ definitely is as well in his range. AK/AA he wouldn’t play this way since he know himself as well that he isn’t going to get Called by worse hands. So basically it’s up to the nuts most often. You only beat bluff there and I don’t expect the opponent to bluff in this case unless we know the table dynamics better.
Best of Luck in The Exam! Some more points earned.