Basic preflop equity question.

At what point is a PF equity edge too small to be worth pushing, and how would you determine this? Say that you have no fold equity pre or post-flop, but have a large edge in terms of skill post-flop.

Most of the games I've been playing are very loose-passive with a couple maniacs thrown in. Say a maniac opens, and I'm almost certainly ahead of his range but am unsure if my hand has an equity edge over the hands that will almost certainly cold-call behind me.

Conversely, I open with something in my normal PFR range in a short-handed game, and get cold-called or three-bet in three places or more.

I can't shake the feeling I'm needlessly bloating the pot with holdings which will win only with marginal TP-type hands against a large field that will be drawing correctly much of the time to the turn.

I've taken to only opening hands which have a recognizable equity edge over the field (limping the rest), and I feel like I'm giving up a lot of value by playing so tight (VPIP of approx. 22, PFR of 11 or so) against horrible players. My normal full table PFR is in the 10.5-11 range.

I started with SSHE and understand the concepts presented, but it's been a while since I've played in games this loose, particularly in the different short-handed environment.

On another note, I've been taking longer shots at a new level with a short-ish roll, so it's possible that I'm unconsciously trying to reduce variance (which I assume will skyrocket pushing small edges PF in games like these).

Edit: Eh, I'm probably finding a way to justify lower-variance play to myself. EV+ is EV+.