[Rubeskies]

Relating to hand 4, you raise because of what happened. There are a few cards that can come to hurt your equity. The one that came is one in the form of a K. The other is a 9 or T filling in what could be a very possible gutshot requiring a card "In the Zone". You have a strong draw but your made hand is still vulnerable. CO is still in the hand so you want to protect from him plus he may call 2 incorrectly anyway seeing as he doesn't mind cold-calling.

Another reason is that the guy who bet out might 3-bet you with a lower flush draw. Even though he is drawing dead, he thinks he's drawing live. People bet out into the preflop raiser sometimes with a flush draw hoping to get it raised so they can 3-bet. This would be great for you.