Some banks will allow you to open accounts without residency..you just wont be given a cheque book or credit ( its generally just an account with ATM card)

Not a good position to be in, contract wise.
Is there a reason its taking so long...hate to see you pay the money and contract details change (etc)

Keep pushing the company, as schools finished today, and most wil only have skeleton staff on for over part of the holidays, so you need to get this sorted.

And, yes, if not paid up, you will certainly lose your place if someone else comes along who can pay everything upfront.