Flop: I think vs a weak/bad player you should always fastplay by raising all sets and many straights as well.
Turn: You clearly need to call Turn. Raising is overplay, you have plenty of implied odds vs straights (when you pair to quads or a full house), and you do beat some flush draws and random bluffs.
My plan would typically be to call Turn fold RIver - pretty suicidal for people to double barrel this turn as a bluff when you're calling 2p/set/straights here and you still have plenty of straights left on the River so it's not exactly a good bluffing spot for him
Regarding labelling him as a maniac - there's a difference between an aggro maniac (high VPIP and PFR + high postflop aggression) vs a passive whale (high VPIP and low PFR, low postflop aggression)
Vs the former I will consider calling down with a set even, vs the latter you clearly need to fold River unimproved