1. I just got my baby last month, was the same size as yours and now its 4 inches. It isn't even fully grown and can eat about 10 crickets, 5 night crawlers, 3 adult Dubias a couple of pachnodas and a locust in 24 hours(that's his record). So they will eat loads when fully grown.

2. I have no clue. It's not inevitable if you keep your frog at warm temperatures all year round and I don't think it's necessary.(not 100% sure though)

3. I dust mine with calcium+d3 every other day and dust about half of what he eats. I dust with multivitamin once a week and dust all the prey items. Don't dust to heavily though, just a fine coat should cover the insects or whatever you feed him/her.

Bear in mind it will eat loads more if its a male when its an adult just to sustain its large size. I'm just taking a guess her but I think it's a male but its stil way, way to young to tell. Anyway keep us updated on your frog. Hope I helped.