Curious Hand

I'm on a downswing, and I feel like I'm getting run over pretty good at my tables lately.
I f-ed this hand up real good. I need feedback to see if I overplayed this hand by getting too cute. Opponent is largely unknown, but table has been raising a good bit. Aggression is abound.
Preflop: Marginal call, but one I find profitable against most unknown opponents at 6max.
Flop: Bet flop, evalutate a raise?
Turn: Check or fire again?
River: Call or fold as played?
------HAND 1------
Game #2562979584: Hold'em NL ($0.25/$0.50) - 2006/06/02 - 12:46:26 (ET)
Table "Sergio" Seat 3 is the button.
Seat 1: Jean16031 ($67.40 in chips)
Seat 2: pokplay88 ($30.06 in chips)
Seat 4: Reyzemup ($46.92 in chips)
Seat 5: PassDSuga ($45.10 in chips)
Seat 6: metalface ($82.55 in chips)
Reyzemup: posts small blind $0.25
PassDSuga: posts big blind $0.50
----- HOLE CARDS -----
dealt to PassDSuga [Jc As]
metalface: folds
Jean16031: raises to $2
pokplay88: folds
Reyzemup: folds
PassDSuga: calls $1.50
----- FLOP ----- [Jd 7h 5d]
PassDSuga: checks
Jean16031: bets $3
PassDSuga: raises to $10
Jean16031: calls $7
----- TURN ----- [Jd 7h 5d][Th]
PassDSuga: bets $16
metalface sits out
Jean16031: calls $16
----- RIVER ----- [Jd 7h 5d Th][Kd]
PassDSuga: checks
Jean16031: bets $15
PassDSuga: ?

Example from yesterday. This seems to be happening a lot lately. People don't float that much at 50NL do they? I'm guessing I'm beat by a Q with position on me or a set of 8s/Ts eh?
-----HAND 41------
Game #2551733084: Hold'em NL ($0.25/$0.50) - 2006/06/01 - 12:59:40 (ET)
Table "Nekkar" Seat 2 is the button.
Seat 1: zaman1984 ($49.73 in chips)
Seat 2: Rocsteady ($30.75 in chips)
Seat 3: Daily ($53.40 in chips)
Seat 4: Feed_Me ($45.58 in chips)
Seat 5: PassDSuga ($68.85 in chips)
Seat 6: 8__ace ($38.50 in chips)
Daily: posts small blind $0.25
Feed_Me: posts big blind $0.50
----- HOLE CARDS -----
dealt to PassDSuga [Jh Jd]
PassDSuga: raises to $2
8__ace: folds
zaman1984: calls $2
Rocsteady: folds
Daily: folds
Feed_Me: folds
----- FLOP ----- [4h Qc Ts]
PassDSuga: bets $3.50
zaman1984: calls $3.50
----- TURN ----- [4h Qc Ts][8s]
PassDSuga: bets $7.50
zaman1984: raises to $15
PassDSuga: folds
Returned uncalled bets $7.50 to zaman1984
----- SHOW DOWN -----
zaman1984: shows [Qd Js] (A Pair of Queens, Jack high)
zaman1984 collects $25.45 from Main pot
----- SUMMARY -----
Total pot $26.75 Main pot $25.45 Rake $1.30
Board [4h Qc Ts 8s]
Seat 1: zaman1984 showed [Qd Js] and won ($25.45) with A Pair of Queens, Jack high
Seat 2: Rocsteady (button) folded before Flop (didn't bet)
Seat 3: Daily (small blind) folded before Flop (didn't bet)
Seat 4: Feed_Me (big blind) folded before Flop (didn't bet)
Seat 5: PassDSuga folded on the Turn
Seat 6: 8__ace folded before Flop (didn't bet)

Hand 1: I think you must fold the river, you really beat nothing at all. AQ, AK, diamonds, TJ, KJ, 89, etc.

Hand 2: I don't see any reason to bet the turn, I usually check/call the turn and then fold to a river bet, but a turn check/call on the turn will often times will get you a free showdown.

Agree with aislephive on the first hand.

Second hand, I often just check-call the flop out of position in these situations. A worse hand almost never calls when you bet, but you might get some loose calls on later streets when you check the flop, or induce a marginal or weak hand to bet. Its also unlikely a free card will hurt you much. Another reason I dont like betting is I have no idea how to continue if I get called. It can also be good for metagame reasons.

Betting is alright, I suppose. But once you get called, you have to slow down.

Jand 1. looks like he has an overpair.

hand 2. check/fold the turn.

Thanks guys. I feel like I keep losing these medium to strong hands. I guess that is why they call it a downswing.
For the record, I folded river on the first hand. I keep folding these and am starting to feel weak or bluffed. Thanks again.