The advice reposted above by wonder88 is similar to my experience and well worth paying attention to.
I had no problems with BBVA themselves, but I was employed and paid everything back on schedule. Getting the loan sorted did drag out and your house needs to be a significant percentage higher in value than what you are borrowing. Don't forget to factor in paying your solicitors and theirs as well. From memory that was between 1-2k extra. In your spreadsheet consider the wages you might earn and where you might live; flybe are employing a lot of brand new CPL/IR holders at the moment but your wages won't go very far at all there if you are paying BBVA back £1100 a month, even worse in the likely event that you are sent to ABZ. And all that's before any possible interest rate rise. Your wage will stay the same, but your debt costs will increase.
The bottom line is, you are taking out a mortgage. Except instead of that mortgage paying for something tangible that you could sell like a house, it's paying for a piece of A4 paper to be folded up and shoved in a tiny blue wallet.
For what it's worth, my advice is to get onto an airline scheme, and not even consider self-sponsor/'white tail'. Preferably a scheme where the airline will pay for it or at least guarantee your loan. But I digress, you wanted to know about BBVA.