Hand #1 you should have bet the flop with the set because of the presence of flush and str8 draws and you know you are playing loose folks who could have a piece. You want to bet 1/2 the pot or more to take away their pot odds. In the best case they move in on a worse hand or on their draw and you get it all in with your set on the flop. You actually got really lucky in this hand because you filled up and the river was your gin card completing the other guy's flush. 2nd raiser is a complete donky look to isolate him and play lots of pots with him later.

Hand #2 Fnord is spot on. Reraise him on the flop. If he flat calls or comes over the top you can get away from it. If you were playing super tight and your opponent was even the least bit observant your EP $20 raise screamed QQ or better. His call w/ 10 6 looks stupid but he essentially knew your hand so unless he connected on a super flop like he did he could get away from the hand easy on the flop.