I'm thinking of maybe giving my brother and a friend of mine some GOG games for christmas.
The thing is none of them got accounts yet. Would there be any snags legaly or perhaps or with changing the email address after account creation ?
My idea was basically to make fresh 2 accounts and then buy 3 gift games or so for each of them from my own so they can select the games they want themselves.

you can gift by email address and they can create an account later.

Or if you are not sure about their emailadresses just gift the games to yourself and give them the codes on a christmas card or design a special coupon and print it out.