A few hands from today that really had me thinking I might have made a bad move/laydown. Comments!!!

PokerStars No-Limit Hold'em, $0.25 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

Button ($39.55)
SB ($27.35)
givememyleg ($27.15)
UTG ($24.65)
MP ($23.80)
CO ($70.95)

Preflop: givememyleg is BB with A, A.
UTG calls $0.25, 1 fold, CO calls $0.25, 1 fold, SB completes, givememyleg raises to $1.25, UTG calls $1, CO folds, SB folds.

Flop: ($3) 8, 5, J (2 players)
givememyleg bets $3, UTG calls $3.

Turn: ($9) T (2 players)
givememyleg bets $6, UTG raises to $20.4, givememyleg folds.

Final Pot: $19

I probably should have made it $1.75 or $2 preflop. This is UTG's second hand. He was multi tabling. The turn card didn't scare me, but his line makes me think maybe he smooth called a set on the flop? Maybe I was ahead and he had a hand like 9T and pushed his huge draw. I had no reads, thought about it for a long time and folded. Maybe I'm playing scared... I'm ahead of a decent amout of hands that would push on this board... Who thinks I was ahead/behind here?

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PokerStars No-Limit Hold'em, $0.25 BB (8 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

givememyleg ($28.70)
UTG ($23.55)
UTG+1 ($22.70)
MP1 ($24.50)
MP2 ($25.75)
CO ($78.35)
Button ($25.25)
SB ($5.50)

Preflop: givememyleg is BB with K, Q.
UTG calls $0.25, 6 folds, givememyleg checks.

Flop: ($0.60) 6, Q, K (2 players)
givememyleg bets $0.5, UTG calls $0.50.

Turn: ($1.60) J (2 players)
givememyleg bets $2, UTG calls $2.

River: ($5.60) A (2 players)
givememyleg checks, UTG bets $1.25, givememyleg calls $1.25.

Final Pot: $8.10

OK basically here I am faced with a situation where I can assume fairly positive that I am beat on the river. Yet I still call anyway. I guess there is still a chance I could have the best hand, but why hand besides the straight makes a bet like that? Granted, it is only $1.25, but still.. I am beat so why call. Does anyone fold here?

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PokerStars No-Limit Hold'em, $0.25 BB (7 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

givememyleg ($22.65)
MP1 ($24.25)
MP2 ($48.90)
CO ($66.25)
Button ($6.20)
SB ($24.55)
BB ($10)

Preflop: givememyleg is UTG with J, J.
givememyleg raises to $1, MP1 calls $1, 1 fold, CO calls $1, 2 folds, BB calls $0.75.

Flop: ($4.10) 7, 6, 2 (4 players)
BB checks, givememyleg bets $2, MP1 folds, CO raises to $5, BB folds, givememyleg calls $3.

Turn: ($14.10) 3 (2 players)
givememyleg checks, CO checks.

River: ($14.10) 8 (2 players)
givememyleg checks, CO checks.

Final Pot: $14.10

I am starting to notice I am betting pretty small on the flop in situations like this. Should I pot the flop? Maybe a $3-$4 bet would have gave me a better idea. CO is a solid multitabler. I actually moved from being on his right. He and I respect each other and I knew he was not raising me here with air. I had actually put him on 67 once he raised me... the turn and river seem terrible imo. How to play this better I ask you all.

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PokerStars No-Limit Hold'em, $0.25 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

MP2 ($12.70)
MP3 ($22.10)
givememyleg ($44.05)
Button ($20.75)
SB ($30.05)
BB ($25.60)
UTG ($21.85)
UTG+1 ($33.80)
MP1 ($25)

Preflop: givememyleg is CO with 4, 4.
5 folds, givememyleg calls $0.25, 2 folds, BB checks.

Flop: ($0.60) 4, 8, K (2 players)
BB checks, givememyleg bets $0.5, BB raises to $1, givememyleg raises to $2.5, BB calls $1.50.

Turn: ($5.60) T (2 players)
BB checks, givememyleg bets $3, BB raises to $8, givememyleg calls $5.

River: ($21.60) 7 (2 players)
BB checks, givememyleg checks.

Final Pot: $21.60

Standard or scared?

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EDIT - Forgot to include:

PokerStars No-Limit Hold'em, $0.25 BB (7 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

givememyleg ($25.05)
UTG ($24.30)
MP1 ($21.65)
MP2 ($24.75)
CO ($7.60)
Button ($26.30)
SB ($22.40)

Preflop: givememyleg is BB with 3, 4.
1 fold, MP1 calls $0.25, 3 folds, SB completes, givememyleg checks.

Flop: ($0.75) 6, 7, 5 (3 players)
SB checks, givememyleg bets $0.75, MP1 calls $0.75, SB calls $0.75.

Turn: ($3) 5 (3 players)
SB checks, givememyleg bets $2, MP1 raises to $4, SB folds, givememyleg calls or reraises?

Villian was pretty bad and made a lot of weak showdowns. Flopped the sucker straight, is it good enough to raise turn here? Just call? What then on the river if it comes X?