Firearms in rented accomodation should be fine, so long as you can satisfy the safe storage condition on your licence. This will in most cases involve mounting a cabinet on a structural wall, so check with your landlord that it is OK to do so. You will likley need to make good when you move on. Also, some landlords (and councils) may be anti-shooting so check first...

As for siezure of your guns, I think two factors apply:

1) they would need to be of substantial value to be worth selling against the debt, say >Ł500
2) you must be allowed them if they are tools of your trade - ie if you are a gamekeeper/shooting instructor etc.

Suggest you get some professional advice if you have any that are worth much.. The conumer credit counselling service ( www.cccs.co.uk ) were fantastically helpful when my mother had to declare bankruptcy.

Good luck, hope things improve for you soon.