Hey
I'll be off to Hull this September and I've never been further north than Ipswich :L
It's been my firm for months now actually yet I still never visited. Obviously it would have been nice to but I wasn't too bothered. I liked the course, the area is cheap to live in and it's near some really close friends of mine who went to Uni last year.
Personally I think while it's right to be aware that some places are "unsafe" it's right for it not to bother you
too much. Every area has them. Essex recently had a murder where the girl was just walking to the campus. There's bad people everywhere.
I can't really comment on Hull area, but I can on Essex. I live real close by and visited the campus a couple months ago with my brother who's going there. From what I saw of it, it was really pretty. There were actually rabbits hopping about which was cute :3 Colchester is okay. Is pretty much like any other city tbh. But I wouldn't put too much weight on the area, or let things putt you off. If you prefer the course or have a gut feeling about either then just go with it