1 depends usually its somewhat ok tho.
2 Depends on the source material/naptha. Some people leave it in forever and get white dmt some get black sludge
3 If you do really quick pulls without heating (1 min naptha soak) you will get white dmt because the dmt will want to go to the naptha first.
4 up to you. i dont
5 dont heat the naptha its not safe especially if you work with open flame stovetops
6 shorter = whiter dmt longer = more dmt. Either you do few long pulls or many short ones.
7 both but the naptha sitting longer is more important
8 dont wash do reX
9 collect all dmt at the end
and reX Nearly all these questions were asked multiple times and awnsered in depth already.
Most of these questions are also already responed to in the teks themselves.
Just use a tek like the one where the reX is at the end and you will be fine.
Also its nearly impossible to have bad yield unless you actively destroy the DMT through burning it in solution. The bad yield usually comes from bad tek following and the dmt staying in the naptha due to bad freezer way to much naptha usage.
Just do moar pulls with less naptha till no more dmt comes out.
Also read the forum more. All these questions are simply waaay overresponded. Use the search function or simply use google for your question and add DMT nexus to find dmt nexus results.