6 max SNG Questions

Hello everyone,

I have a grasp of the general strategy for 6 max SNGs, however i have a few quick questions about middle/late game strategy:

1) At what blind levels (relative to chip stacks) does the game become shove/fold?

2) Before this point - when blinds are still relatively large, but not big enough to be shove/fold - what should the general strategy be?

3) What is the best software for ICM? Is the only way to consistently profit from SNGs to put in hand histories and figure if the play was +EV and to try and use this to help with future decisions?

4) How are you supposed to tell if an opponent raises 35% of the time as opposed to 65% of the time? (To be used in ICM calculations)

5) Are there defined push/fold ranges for generic situations, and if so where can I find these ranges?

Thank You for you time.