Ars typically doesn't concern itself with these things. You can, of course, but I would make sure that your players actually want to do this. Hermetic Magic is pretty good at making buildings, if a bit of vis is available, and magi have the spells, of course.
2)Well, none have given special attention, but let me ask, did you suggest they do so? In most Ars sagas this is the role of grogs and companions, to fill in the mundane gaps of knowledge that magi will invariably have. While it's true that magi do get a lot of experience points, magi just out of gauntlet have had to spend 90 of their 225 extra xp on compulsory skills for magi (Magic Theory, Latin, Artes Liberales, Parma Magica). Being magi, one would expect them to spend the bulk of remaining XP on Arts...
On item 2 - you might find their lack of skill to be a useful hook. Perhaps they need to promise favours to gain short term assistance which then should be repaid?
