50g mimosa is enough for 10 doses if taking it orally together with a MAOI. Better start with less even, like 3g mimosa a dose, until you know your own sensitivity and the batch
As for the FASA vs evap, I never made a side-by-side test to see if there is differences in yield. Around 30% of the weight of dmt fumarate is the fumaric acid molecule, so you calculate that to know exactly how much dmt you have once you get your fumarates..
You cant really compare 'which is stronger', both are DMT. DMT fumarate is good for storage and oral ingestion, but to smoke it you have to convert to freebase first as described in the WIKI. Personally I would say that salting with fumarates is recommended simply because xylene is very nasty to evaporate, smells like hell, and mother nature sheds a tear when you do it (

).. Salting will prevent this, plus it also means that after retrieving the fumarates, you can reuse the xylene (once you have washed it several times with water to remove acetone).