Yes, you take all your stuff back at the end of each term. It's not that big a deal, you'd probably take about half your stuff home each term on a longer let anyway and it's scarcely worth spending nearly £1000 more just to avoid the hassle of a bit more packing if everything else is the same to you.
You have a Freshers' Fortnight, but the timetable does begin from the first Monday - which for the first week is almost all admin-related and little work is involved other than finding your way around. It isn't as if you can't get drunk, if that's what you're worried about.