IF wrapping the knees makes them feel better and allows you to squat it is probably a good idea. I have seen the info that says not to, and i have gone back and forth on this until i met people who have actually been squatting for a long time and wrap quite often. and I am not sure anyone has ever been harmed from wrapping the knees. I probably wouldn't recommend comp tight but i don't see how a moderate wrap is bad.
As for leg extensions, they are used in rehab of the knee, but i think it is more for after reconstructions, when the muscles have completely atrophied around the knee, and done pretty light. Leg extensions bothered my knees like nothing else. As a matter of fact it is the only think that has bothered my knees. I cannot see wanting to do these if you have wear and tear knee issues. I would like to here some info from a PT on this.