Opinions may very but I do not believe that grease is needed on the outside of the bolt. It rides on delrin (i think) rings which is all that is needed. I have been using VSR10s for over 4 years and have NEVER greased the outside of the bolt. If you do.. dirt and gunk may stick to it causing you all sorts of problems.
As for the inside of the bolt (cylinder) use 100% silicon grease.. not oil. I use some made my Dow Corning. Apply a very thin layer where the piston rides in the cylinder and a bit on the piston o-ring.
I have a PDI v-trigger and I use a bit of white lithium grease in there. It seems to keep everything working well and, atleast I believe, lightens up the trigger pull a bit.
Nothing else needs grease. Ofcouse, you may wish to pick up some light weight 100% silicon oil or spray to clean your inner barrel. Dont get any on the hopup rubber and make sure you wipe it all out before you go shooting.
After your maintenance is done, you may need to shoot a bunch because grease could make its way out of the cylinder and onto the hopup rubber. not much you can do about that. Just pop off a bunch of bulk BBs until it starts shooting consistantly again. It may take 50 - 100 shots.