I normally do alright in MTTs but I get a bit lost if my stack reaches 20-15bb, I'm not too sure if I should be loosening up (i.e raising my 93o from CO to try and get some chips) or just focusing on restealing, or both.

Raise 2.5bb if you think you can steal. Steals and playing at 15-20bb are about meta-game mostly but you can steal or raise 2.5-3bb and play here. And go n go is good now. When you're in the sb or bb if co or dealer raises to 3bb you can re-raise to 9-9.5bb and shove on any flop.

And the thing i see too much on low stakes is when you raise to 2.5bb most of the time players don't give you a credit for a hand and if you're playing KO tournament, you can be sure re-raise all in is coming behind you.

At about 15 bb the reraise all in is the most powerful tool. Once you hit about 20 I'll echo what ERO said w/ the go and go.

As far as open raising, yes your range should open up. But reads on the players, antes, stack sizes etc... should dictate just how much. 93o from the cutoff is a little extreme. 2 suited cards above an 8, or 2 cards above a 9 is a basic range. Add small pairs and some suited connecters as well.

That is a good base but again if you have a BB that will call light, then your range has to tighten unless you plan on outplaying him after the flop (which can be difficult w/ 20 bb's.)

Overall yeah it seems that you are on the right track. Just keep in mind there is a fine line between aggressive and suicidal.

Hope this helped!

ok i was gonna type about a bunch of stuff but then i realized bond did it way better than i could here

QFT, I was just too lazy to find the link

Resteal, resteal, resteal, resteal, particularly out of the blinds to a late position raiser