piercing

i have many questions but when the time comes to ask i forget.... firstly ....are we all children of Adam PBUH or are we all descendants from that era but of different individuals?is nose peircing haraam?and also.... can a muslim actually marry another muslim of a different nationality..i.e. arab marrying pakistani...i mean if not does this not go against what allah said about discrimination in islam?and also....i want to be a lawyer...should i?i mean islamically is it allowed?