Ok, go easy on me here, if I say something that sounds silly or stupid don't abuse me... I really don't have a clue on this stuff when it relates to cacti.
1: Do cacti self pollinate (in particular echinopsis and mammaliria)?
2: If they do NOT self pollinate what are the vectors for pollination?
3: If they do NOT self pollinate and we lack vectors what are methods for pollination, you may yse terms like stamen, anther, stigma etc...

4: Does pollen cross and should I seperate flowers I do not want to cross pollinate with?
5: Do they all produce small (or large in the case of dragon fruit) fruit bodies like pictured in my
M.prolifera ?
6: Assuming I do get seed what is the best way to dry them out ready for selling, planting etc?
Sorry for the bombardment of questions but I appear to have a specimen wanting to flower in the next couple of months (maybe - I noticed the beginnings of a bud today).
7: If they do self polinate is there much genetic variation?