short stack strategy

You should try to get your hands on some Nash-range chart. A good one is to be found in the book "Kill Everyone".

Especially if you have <15BB the nash ranges are extremely important.

For 15 to 30BB stacks it is hard to give solid tips.
I would resteal a lot with 15 to 20BB vs late position open raises (by pushing allin).
20 to 30BB is always a bit hard to play and most people have their dificulties with these stacksizes.

Regards,
Asaban

ye i am 3/4 way though kill everyone. i have 15 and below down its just 15-30 which im unsure on

Maybe it would help to watch some of our videos and have a look at how other coaches play with these stacks. In the end there is no perfect way to play them. It depends on your opponents and the tournament structure.

Regards,
Asaban

Are nash ranges only for HU pots?

They are meant to balance your first in pushing range. Therefore you can't influence how many people participate anyways

Callingranges are a bit harder to work out. If your opponent pushes according to nash you can easily equilate your equity against his range. If he doesn't you will have to adapt. Same goes for multiple opponents.

Regards,
Asaban