1: If you bet bigger on the flop you can get an easier allin on the river.
Without an image you won't get called by J- very often imo and he might not have Jx on the river ever. With your line I'd bet 1/2-2/3 pot.
I also like a flop c/r more than a lead, although I guess it depends on how you play these flops with other parts of your range.

2: Standard flop raise imo, your range is strong as UTG raiser, you can get it in, check behind turn and all sorts of things. As played I'd bet the turn. River I'd check behind because underpairs are calling you all day imo and he has those a lot.

3: Fine, although I'm not minraising rivers very often. If he's bad enough to not know that you're never bluffing with a minraise there's some value imo.
I also wonder if it's a profitble open preflop if villain is a loose fish (was he?) and when you're not sure how thin of value you can get here.