As for filters, normally the filter of .22um is better than .45um. despite taking long time to filter. I recommend PTFE filter. Because it has the most inert material with a PP backing.
Some guys heat raws with 212F, but 150 F is a suitable temperature. As for such low melting point products such as test enan and deca, almost 120 F is enough.
You could mix the oil and raw powders well before filtering. However, you also could filter oil first, and keep the warm oil mixed solution with the same temperature. Because it could speed to filter the solution in your next steps.
Hope my suggestions could help you! Any further questions, welcome to shooting me.