It is possible to learn the theory exams for the PPL as part of the course, with the exception of the RT practical test, although the lecturer for the PPL subject can do the test for you, so no hassles there. As for FTO for the flying, you can train wherever you like.
If you gain your PPL, this can be counted as one of the units towards the degree, and the theory exams would be another unit. The theory exams would be taken during you first year, and you'd need to have your PPL by the end of summer, just before your second year (if you were studying full time), although I think you can still do the flying in your second year if you haven't got it by then, as its a second year unit. If you already have your PPL before you start the course, then you are credited both units.
When I was there you could also study the theory for the IMC rating as one unit on the course (year two if I remember correctly). Not sure if that units still available though.
This link
Shows you a breakdown of the course. If you click on the Purple unit codes, It'll show you info regarding that unit. The PPL Theory unit code is: CA1004. The PPL flying is: CA2000, and the unit for the IMC theory is CA2080.
For accomodation, you mentioned living on campus, this is not possible as London Met isn't a campus university. It consists of a collection of buildings in central London. There are halls you can live in, which are all within a few miles of the uni. I lived in claredale halls in the first year and had the time of my life!! I never knew my liver could take so much of a bashing, and very much recommend it.
If you havent applied for halls you need to ASAP. Further details
here
and
here
The other two halls available; Sir John Cass, and John Bell House are both in dodgy areas. The location of Claredale isnt fantastic, but I think its the better of the three.
The Air Law module in the 3rd year is different to ATPL Air Law although there are some bits which are the same. The Degree module is more concerned with liability of Airlines/Airports, whereas ATPL Air Law is concerned more with rules of the air etc.
There are finance units you can take in the 2nd and 3rd years which obviously involve maths. I found the 2nd year one hard, and didnt do it in year 3 (we had various options). The maths is a different type to that needed for ATPLs. If you can do the maths/physics brush up pack they send you before your ATPLs, then you shouldnt have any hassle with the maths. Thats what its designed for - a brush up! You dont need to be A'Level standard or anything.
The first year is the same across the BSc and two foundation degrees (management and Pilot pathways), so you can transfer between them anytime up until the start of the second year.
Are you planning on doing your ATPLs at London Met after the Degree?
Have you had a look around the uni? The PPL/ATPL side is taught at Tower hill, and most of the degree specific modules are taught at Moorgate, so if you visit, have a look at both locations.