Well I don't think they want a family of four in a room next to normal age undergrads.
Even undergrads don't have to live in college. They can request for this and the colleges can let them live elsewhere. I knew someone who went to Oxford and lived in the Lake District. Only showed up once a fortnight.
Nopes. STEP I 2011 was released on goodwill. STEP I, II, III 2014 was from FOI, STEP I, II, III 2015 and presumably further years are also on goodwill.