
So, my winter project is stripping down me trusty ol' motorcycle, and polishing said turd with rattle-cans of paint and some new nuts and bolts.
I could do with a bit of an idiots guide to identifying what a screw/clip/threaded part is made of. There are a few rust-marks around, but very few of the fixings seem to be magnetic, so I'm thinking some places used to have mild steel washers which are now missing or something. Shall I just replace everything with stainless, including the washers, fixings/clips etc? Any cases where stainless is a bad idea (e.g. when fixing into a lump of aluminium like the radiator ends?)
Obviously, where specified I'll use the OEM high-tensile bits, but this question is mostly about the bodywork and cosmetic stuff.
Secondly, a similar idiots guide to grease. What to use on different fixings to ensure they don't corrode or gall? I don't have any moly or lithium grease, but do have a tub of copperslip.. would that do or is it worth getting something specific to each combination of metal-metal application?
Or does it just not matter?

Ta.