November 17 losing hands

Few more hands that I got stacked:

http://www.pokerhand.org/?3466519
quads on river beat my nut flush on river. but not sure if i could have prevented this from happening

http://www.pokerhand.org/?3466523
villian was 25/16. he basically just called his way to the river.

http://www.pokerhand.org/?3466530
villian is 27/11 agg 3. I've been in several pots with him and he seldom backs down, the fishy check on the river. I had to bet. or not?

http://www.pokerhand.org/?3466543
villian 31/1. Limped in with AQo. On the turn I think even if i shoved he'd still call with TPTK, and get there at the river.

Please comment. These were the 4 largest pots I lost last session.