NL Holdem, AK, and firing the second barrel when u miss the flop

[MrBruno]

Just starting to play NL holdem, and am curious as to what others have to say regarding the following situation...

- Assumptions:
- 25NL or lower
- Big stacks (~100BB) at the table.
- Usual mix of loose and tight opponents but w/no maniacs.

- Hero is dealt AK utg (or EP, or 1st in) and makes standard raise (3-4xbb).

- Scenario #1: A single caller with position on Hero.
- Scenario #2: 2 or more callers with position on Hero.

Hero's usual line...

Scenario 1: Hero makes a Cbet and gets called. Hero check/folds the turn unimproved when villian bets.
Q: What's the plan on the turn if another brick falls and Villian bets? Should Hero fire the second barrel (w/half PSB) to try and take the pot?

Scenario 2: Hero checks and it's checked around to see a free turn card.
Q: Again, on the turn, what's the plan? Fire the second barrel? Check/fold unless the board pairs one of Hero's cards?

In both cases, I think I'm being pushed out of pots on the turn (or river) when my opponents put me on AK (ie am I being overly weak-tight in these situations?)

I realize there are no cookie-cutter approaches to this and the standard "it depends" applies, but I'm curious to see what most of you would do in these situations.

Thanks!