Its also worth noting that in Guernsey currently (not sure about Jersey) you can off-set mortgage interest against your income tax. My better half is a Guernsey local and her sister doesn't pay a penny of income tax until she earns over £27k.
There is talk of this allowance being withdrawn however given the recent 0/10 rule being introduced which brought corporation tax to 0% for qualifying companies - gotta fill that budgetary hole somehow!
I would expect that you would be granted a local license if you got a job with one of the above airlines, although unless you make captian by its expiry I wouldn't hold out too much hope on getting an extension (got a a fair few well qualified / highly skilled friends from the UK who are there on 5yr licenses and face the same problem, despite the significant cost to their firms of filling their positions).