1) I think you will need to come first because you need to meet certain criteria before you wife can join you. They're outlined here: https://www.ch.ch/en/family-reunification/
The Swiss authorities will want to know that you earn enough to support you both while you're here.
2) I'm not sure if non-EU student dependent permits grant work rights as well as residence, but I assume they're similar to the normal permits in which case it will depend on which you get. If you get a one year B permit then although she will only have residence rights she can look for work and it shouldn't be too difficult to add that to her permit. If you get an L however, then it will be much more difficult for her to find a job because employers here have to give priority to Swiss/EU nationals when hiring. https://www.bfm.admin.ch/bfm/en/home...zulassung.html
This should apply to non-EU dependents with B/L permits too, but the Swiss authorities have waived that for holders of a dependent B. L dependents still need approval from the Swiss authorities before they can be hired.
3) If she doesn't get work rights then no she can't earn money from any other activity. Residence means just that, live here only, but not earn money from any source.
Note that she is not allowed to freelance on either a B or L without permission from the Swiss authorities. Being self-employed effectively affects both her permit status and the various taxes/insurances that have to be paid. https://www.ch.ch/en/becoming-self-employed/ http://www.kmu.admin.ch/kmu-gruenden...x.html?lang=en