99 turn bet or check question (leads on to more general theory Q)

[nextgenneo]

I am pretty tired and apologise if this is basic. I think I've just been overthinking some things recently.

Anyway, heres something I have been messing up with recently and here is an example. I think it just has to do with me overvaluing the show down value of my hands and not wanting to turn them into thin bluffs.

Hand 1

Vil is a 26/22/3.5 aggro reg

Party Poker - No Limit Hold'em Cash Game - $2/$4 Blinds - 6 Players - (LegoPoker Hand History Converter)

SB: $336.99
BB: $647.20
UTG: $112.60
MP: $1,615.50
CO: $559.80
Hero (BTN): $394.00

Preflop: Hero is dealt 9[img]/images/graemlins/diamond.gif[/img] 9[img]/images/graemlins/club.gif[/img] (6 Players)
UTG calls $4.00, MP folds, <font color="red">CO raises to $20.00</font>, Hero calls $20.00, 3 folds

<font color="blue">I often 3-bet here but I also call this spot with the limper being a donk who will call a lot and stack pretty light.</font>

Flop: ($50) 3[img]/images/graemlins/spade.gif[/img] 6[img]/images/graemlins/club.gif[/img] 2[img]/images/graemlins/diamond.gif[/img] (2 Players)
<font color="red">CO bets $35.00</font>, Hero calls $35.00

Turn: ($120) 7[img]/images/graemlins/spade.gif[/img] (2 Players)
CO checks, Hero checks or bets?

<font color="blue">So at this point what is the main reason to bet because we could easily be c/r bluffed in this spot from a solid aggro opponent and he rarely has anything to call with right? So to me it seems our hand is too thin to get value from.

Problem with checking though is a lot of times some sort of scare card will come on the river which the opponent will bet. So what are the merits of betting / checking here and what do most people do?</font>

Hand 2

Here is a more fitting example of the concept I am trying to really grasp:

Opponent is playing 28/20/3 so is very aggressive.

Party Poker - No Limit Hold'em Cash Game - $2/$4 Blinds - 6 Players - (LegoPoker Hand History Converter)

SB: $400.00
BB: $400.00
UTG: $450.60
MP: $406.00
CO: $399.20
Hero (BTN): $453.40

Preflop: Hero is dealt 6[img]/images/graemlins/diamond.gif[/img] 7[img]/images/graemlins/diamond.gif[/img] (6 Players)
3 folds, <font color="red">Hero raises to $14.00</font>, SB folds, <font color="red">BB raises to $50.00</font>, Hero calls $36.00

Flop: ($102) 3[img]/images/graemlins/diamond.gif[/img] T[img]/images/graemlins/spade.gif[/img] 7[img]/images/graemlins/club.gif[/img] (2 Players)
<font color="red">BB bets $85.00</font>, Hero calls $85.00

Turn: ($272) 9[img]/images/graemlins/heart.gif[/img] (2 Players)
BB checks, Hero checks or bets

<font color="blue">So after floating here we are best to turn our hand into a decent semi bluff (extra GS outs) and shove right here because if we check we are giving a free card and its probably very unlikely that if he shoves river and we call we are good because our hand is way too thin.

So even though our hand is probably good right now its best to shove?</font>