You'll find it easier on mat fiber. Most RC surfaces don't have enough "tooth" to hold the oils, unless you spray them (Marshall's makes something called Pre-Color Spray). I hope you're also trying pencils. They're great for detail areas.
"This week's project has turned into Bromoil prints and I also have easylith and bleach on the way, lol. Nothing like taking it one thing at a time, huh?" Now you're sounding like me. I've been struggling with Bromoil for a few months. Close, but no cigar... Please post with your experience.
Agreed, forget doing oil on RC paper. It won't soak in and will just rub off and look poor since it sits on the surface. Even glossy FB is not ideal, in my experience. The ideal medium is matte finish fiberbase paper. Also as mentioned oil pencils are great for small areas. A white plastic-type works great for removing overpainted areas. Something like this: