100NL - river decisions

[XTR1000]

#1 BTN is 15/8/2.1 semi reg, haven´t played him for a while. He´s kinda tricky, I folded to two possible floats before. C/c or b/f river?
$0.5/$1 No Limit Holdem
9 players
Converted at weaktight.com

Stacks:
UTG ($95.40)
UTG+1 ($95.20)
MP1 ($16.85)
MP2 ($17.00)
MP3 ($122.10)
Hero ($100.00)
BTN ($99.30)
SB ($20.50)
BB ($137.10)

Pre-flop: ($1.5, 9 players) Hero is CO
5 folds, Hero raises to $4, BTN calls $4, 2 folds

Flop: ($9.5, 2 players)
Hero bets $7.5, BTN calls $7.5

Turn: ($24.5, 2 players)
Hero bets $16, BTN raises to $32, Hero calls $16

River: ($88.5, 2 players)
Hero ($56.5)?

#2 SB is 13/8/2 regular. My image is solid, river bluff raises are very uncommon and I doubt he´s betting weak to induce a raise. I´m basically turning my hand into a bluff and have no idea if its a good play.
$0.5/$1 No Limit Holdem
9 players
Converted at weaktight.com

Stacks:
UTG ($20.00)
UTG+1 ($63.95)
MP1 ($29.30)
MP2 ($74.60)
MP3 ($20.00)
CO ($100.00)
BTN ($18.50)
SB ($117.95)
Hero ($100.00)

Pre-flop: ($1.5, 9 players) Hero is BB
7 folds, SB raises to $4, Hero calls $3

Flop: ($8, 2 players)
SB bets $5, Hero calls $5

Turn: ($18, 2 players)
SB checks, Hero bets $12, SB calls $12

River: ($42, 2 players)
SB bets $12, Hero ???

[spoonitnow]

Hand 1: You can't bet/fold this river -- you don't have enough money. I think a check/call on the turn is better for pot control and to take advantage of the fact that you think he could have floated you twice. Also, if he is ahead on the flop, then this allows you the cheapest option to see a river to hit your flush. As played, if you're going to get it in, I think a check/call is best. Nothing is calling a push here that you beat.

Hand 2: I tend to check turn and call river here. You don't want to be playing a big pot in this spot, imo. As played, calling is probably fine because you're getting 3.5:1.