Paint and Body Any non oil resistant parts in engine bay?

Technically oil is flammable, so really be careful where you spray it to prevent it from getting hot and igniting.

For the most part most of the equipment in the bay should be oil resistance as part of speccing the proper vac lines and such. ANy post-production replacement however might not be proper spec. For instance vacuum lines. I can't think of anything that would break down with oil though. If anything, engine bays are put together with the thought of oil leaks occuring at some point and just coating everything. For the most part I would not spray the engine directly and just do the fender aprons. First start, i'd let it idle up to temp and let the oil in contact i with hot parts burn off and stand by with a fire extinguisher.