am about to tackle my rear brakes on a 2000 legacy wagon, and am wondering amongst other things is, should i invest in a torque wrench ? as i have seen other post alluding to torqueing the caliper bolts, and what is the proper torque on these bolts?

A torque wrench is a must for many things, particularly aluminum (like your engine). Your brakes are steel but not a bad idea to toruqe them.

 

My 97 Legacy:

 

front lock pin=25-33 ftlb

rear lock pin=144-204 INCHlbs

 

rd

Should anti-seize grease be used on these bolts??

I don't. But I fail to see how it would hurt.