How was my line here?
almost as bad as folding the river because you didn't boat.

Should I have raised?
yes.

At what point?
on the flop, after not raising the flop, on the turn

My basic reasoning through this had was did villain flop the straight - if so would he lead out with a pot sized bet???
Some people are very straight forward. Granted most at the $25 try to get tricky, but not all.