Not a bad weight, not great but certainly decent and lighter than the stock wheels
I wanted to run 16x8 for street tires but nothing even in 4x100 would fit my needs without costing a small fortune and
Pretty sure you would have to do the 4x100 conversion to fit them under the fenders which can be pretty cost effective done some ways as not likely a spacer and that offset would fit under the fenders and as mentioned not a good thing to have zero offset anyway.
The brake rotors do not have to be machined as they are hub centric, you can drill them on a drill press or with a decent hand drill if you mark, punch, pilot hole first(not always needed but helps keep the holes where you want them and easier on bits to step up a few times.)
Hubs, good idea to have a machine shop do them or gun runner on the site here.
Good think about this, lots of 4x100 wheels to pick from if you ever want to change