This looks like some excellent work. I find your writeup very impressive. A lot of folks including myself and jhudler have talked about making a bearing material substitute on the monstrous E/G thread but nobody besides you has done it that I am aware of.
As for mold releases, a commercial silicone mold release for epoxy is only about $10 US a can and it works wonderfully. I use the EaseRelease 200 from Mold Release Agents for Mold Making & Casting from Mann Formulated Products. Because this worked for me, I haven't investigated other alternatives though it is possible that some others might be even better.
As for teflon, it can be sourced from the internet, even directly from DuPont and because teflon parts are sintered for manufacture, there are a wide range of particle sizes available.
I can tell you that increased temperature cure generally improves the temperature resistance of a set epoxy material but the exact temperature to use and the cure cycle are specific to the epoxy and hardener. If you're really brave, call Huntsman and ask about the best cure for the epoxy you're using. The 5 minute epoxy will generally set up more brittle than the long cure stuff cured at higher temperatures.
A bit of googling turned up a Canadian company lowerfriction.com with tungsten disulphide which is said to be far superior to molybdynum disulphide in terms of coefficient of friction $50 us per pound approximately. They also have spray can versions that embed a semipermanent lubricant layer into the items that they are sprayed on. This looks interesting. Another possibility now that we are in modern times is to replace the calcium carbonate and graphite with hexagonal boron nitride which also appears to be available for about $50 US a pound.
Additionally, a titanate coupling would probably increase the strength of the material and the temperature resistance. The only way to get this though is to talk with Kenrich petrochemicals and I don't know whether they do business outside the U.S.
Drop me a PM if you want to talk. I've learned a fair amount over the last several years working on epoxy granite and have a fair reference library. Even though I am on unrelated extended travel right now, I do have a copy of the Lee and Neville Epoxy Resins handbook with me.