Hi, lightcarier!
And welcome to our SnG discussion forum.
As a general guideline, I would suggest reading SnG Strategy by Collin Moshman. It helped me a lot when I started studying SnGs. Of course some of the data is a bit outdated, but, overall, it's a great and useful read that will be in a good help for your game.
What we push or call bvb depends also on how many players are left, how risk averse are we against this particular opponent, our image, eff. stack sizes, type of SnG(whether it is FR, SH, pay out structure) etc. etc. You pointed out some of these already.
If we play 9-10-man SnG, we are, say, 7 handed for 10bb eff., if opponent calls like 20-25% of hands, I push any 2, if he is a reg, I push nash(somewhere around 55-60% or so). Vs a reg, I will call something close to nash if he pushes over me, vs a fish- I will be much tighter unless I have a certain read, because fish usually tends to push a tighter range in the blind battles. He will much rather limp(loose passive) or raise/fold-raise/call depending on his mood/hand/game flow.
For 7bb-pretty much the same story, any 2 vs a fish/tight unknown, about 65% vs a reg or so.
For 5bb- I don't think any 2 will be a big mistake on the micros as ppl usually don't call as loose as they should(fish doesn't adjust to decreasing eff. stack sizes), but still-take your trashy range out vs decent regs. I won't push 82o f.e.
As for the videos- our site is full of valuable SnG content. Whatever you pick will be helpful.
Cheers!
SnG Mindset Blog