There is no way you can get yourself in £10k of debt if you spend sensibly, budget and work in the holidays. The student loan is the best loans you can ever have in your life with low interest rates and no payback until you earn over a reasonable thresehold amount. Tip: Don't bother with a car. You don't need it at uni and trains usually work, and they literally burn money.
Where are you going to get the money to learn to fly without a degree: sure there are well-paid non-graduate jobs, but the monetary advantages of a degree far outweigh the disadvantages of 3-4 years not fully earning. The majority of the competition for flying jobs will by your time have a degree, you will have missed out on the lifestyle which the rest of your schoolmates have had, and you will kick yourself for the rest of your life. You have the easiest opportunity to get a degree while you are young and just out of school. There is not point in making it harder on yourself and closing opportunities by not doing a degree: why the rush to get into flying. You may say economic climate, but this is not as predictable as many may lead you to believe: 5 years may be massive recruiting or none at all, and even then waiting a little longer is not that much of a hinderance. With the prospect that even BA will have to increase retirement age to 60-65, getting a job at 25-28 is not much of a disadvantage in reality.
Get that degree!