I don't like the river raise personally. With a 4 card straight on the board he is likely to have a str8 as well or a flush. I really doubt that he is going this crazy with AA or KK, and after the turn action I am only raising if I have a read that someone is retarded LAG.

That being said .5/1 players that have a 53 VPIP do tend to be pretty retarded, and if they're retarded enough to limp/cap with a hand that currently beats you, then they are retarded enough to be doing this with AA. Though I do think the river cap is likely spewing.