Maybe it's just me being slow but I don't understand.
You say you will go on to earn up to 10 million in the next ten years, but want to know if the airlines will accept you without GCSE's ?
Firstly, no one really cares if what you say is true or not. I don't mean that in a malicious way, purely in the sense that if someone comes on a forum and chooses to give a story, it matters not whether the story is true. You could already have 100 million pounds or you could end up never having more than £1000 to your name. The details are irrelevant. It's only yourself that will ever know the truth.
So with a prosperous business ahead, why would you want to work in an airline job ? Depending on your point of view and where you are in the industry, the job is not all that bad (or good!) but certainly not a logical progression from starting a multi million business at such an early age. If the forecast of business is true, you will own your own private jet and should you wish to fly purely for fun, then you will buy some suitable aerobatic toy.
So the question is, are you preparing yourself for a business failure and so hoping to fall back on the airlines or are you feeling the need for admiration from strangers over the internet about a huge succesful business you may own in the future ?
All the best whatever happens. If you make in the business world, but then decide to join the airline, I'm sure they'll overlook the lack of GCSE's weighed against the business sucess you will acheive
