[Mister Z]

Hand one reminds me of a hand I posted a little while ago that you replied in actually (I think). The difference here is that this guy is a LAG. However, I don't know if this is enough info to make us believe that villain would make a stab at this river empty-handed often enough to make a call worthwhile. Also, most LAG's would call with Ace-high on a flop like this - I think betting this turn has enough fold equity in it to be profitable, and it will probably get you to a free showdown (which you will probably win pretty often). So you have 3 options

1) betting the turn and checking the river - gains fold equity, gets the S/D cheaply
2)checking the turn, calling the river - May encourage a weaker hand to bluff? not enough on this board or against this opponent IMO
3)check turn, fold river - wins the least, loses the least, would be preferred against passive opponents

2nd Hand:

Hmm - this board makes your turn check-through more effective IMO and would encourage a lot of LAGS to bet their pairs when they might have folded them on the turn. Plus you could very likely be C/R'd here which could be costly. I like the line you took here.