Hey Ox! Welcome to Peregrine!
The first set of questions, Gift and I will be putting together a little info thread on Earth and the Galactic Federation in the next few days that will hopefully cover everything you need to know. For now, we've been going with a "if you're making an offworlder and you want something to exist, ask us and we'll tell you if it's plausible" kind of thing.
As for the second set...
-Translation tech! It's fast! It's cheap! It's easy! It's more-or-less foolproof!
-That's a good question. I CAN tell you that dragons will not fit on the Peregrine. If you're planning on playing an Impressed offworlder, that's something they will have to figure out for themselves.

-Probably nuclear. It still takes years to get between star systems in this canon, so it's not like they have a fancy mass effect core or a hyperdrive or anything.
-At Peregrine, candidacy is a very relaxed kind of thing. Anyone who's in roughly the right age range and physically and mentally healthy is welcome to Stand when the time comes - R'ley and Sh'ard are of the opinion that the more bodies on the sands, the better. However, it's generally believed by the Pernese that OFFICIAL Candidates who have been formally Searched by a Searchdragon have a better chance of Impressing. As for whether or not offworlders live in the Candidate barracks or in their quarters on the ship, that's up to them. They are still expected to attend lessons, but their crew duties override the usual Candidate chores.