I'm by no means an expert, but I would recommend testing any graphite you want to use because many graphite products now contain polymers.
(I have been trying to find graphite pencil leads to use with hinge making and, so far, the brands I have found have all contained polymers, which I discover when they flame up since no mention of the polymers is on the box.)
Lots of good advice here (which I plan on reading more closely).
If I understand correctly, the soldering clays and the Masking Mud (definitely checking that out), etc., are for protecting from heat, while the Wite-Outs, Liquid Paper, yellow ochre, graphite, slightly wetted powdered red rouge, etc., are for protecting from solder flowing where you don't want it to.
I'd test various products and see what does what I want it to. And take notes. And maybe film it. ( Can you tell I'm still learning?)
All the best,