yes
No Guppies are not moss eaters.
yes the guppies might eat her fin because they it looks like food .
No. its usually not a good idea to put different types of fish in the same tank... one type may be eaten.
I had a problem like this, a couple of fish pregnant at the same time. I would either keep them all the female guppies in the birthing tank or keep them in the community tank and when one of the female guppies give birth put the baby in the birthing tank. I did the second option and it was quite good, just don't overcrowd the birthing tank. :)
No
You should wait until the baby guppies seem to be big enough.
You could add a shoal of guppies and simply allow them to breed which would certainly stock your tank well
Platys and black skirt tetras can live together. Harlequin rasboras, platys, and guppies are smaller than black skirt tetras and would do well together. However, the black skirts nip at fins, so if you have fancy tail guppies it is not recomended to put them in a smaller tank together.
put the guppy fry in a different tank because the adult guppies will eat them
Guppies are community fish that should never be kept alone or in bowls they require large tank, at least 10 gallons.
you can't force them to breed but you can put 2-3 females with 1 male in a separate tank and eventually you will get fry(babies). In my tank i have mollie fry and previously had platy fry whish has now grown up and are adults
Bristlenose catfish