Max value line check

Villain is unknown. I took quite a while to act on turn and river fwiw. Is this the best line?

$0.1/$0.25 No Limit Holdem
9 players
Converted at weaktight.com

Stacks:
UTG ($25.05)
UTG+1 ($25.00)
MP1 ($25.05)
MP2 ($25.00)
MP3 ($27.95)
Hero ($24.85)
BTN ($3.20)
SB ($24.65)
BB ($26.40)

Pre-flop: ($0.35, 9 players) Hero is CO :3h: :ah:
1 fold, UTG+1 calls $0.25, 3 folds, Hero raises to $1.25, 3 folds, UTG+1 calls $1

Flop: :3c: :6h: :3d: ($2.85, 2 players)
UTG+1 checks, Hero bets $2, UTG+1 calls $2

Turn: :ts: ($6.85, 2 players)
UTG+1 checks, Hero checks

River: :5s: ($6.85, 2 players)
UTG+1 checks, Hero bets $6

bet turn $4.

Bet the turn to get more value from 77. Whatever he called with on the flop he most likely isn't folding for a nice $4.50 bet on the turn (unless he has missed overs which people love to float). You're river bet might get called by a small/mid pair but you missed a lot of value here.

I bet/bet/bet here, you won't get his stack unless you play it this way.

Please explain not betting the turn

I thought a turn bet folds out small/mid pairs a lot here (which I think is most of his range) and that checking looks like I have missed overs. Guess I am wrong? Anyone agree?

Also, I honestly wasn't expecting to get villain's entire stack here. Maybe my thinking is off though.

An unknown at 25nl calls three barrels with a small pair a lot. Plus you need value against worse threes.

I'll occasionally check behind on the turn against someone that will call my c-bets with a large range and fold the turn to a second barrel. I'll do it if I think they have a weak hand that won't call a turn bet so they hopefully bluff the river or will call a river bet when a blank hits.

I agree though that against an unkown, especially at $25NL, you should be betting all 3 streets for value almost all the time.