Genghis' post is spot on. I would add that from your post it is clear to me that the military path is not fo you. RAF interviewers are an astute bunch and I am pretty sure you would be wasting your time. Your motivations are not military and joining the RAF is not simply a cheap way to get to the airlines.
Regarding constraints, pretty much anybody can get a frozen ATPL. Getting a paying flying job is a very different challenge. Read some of the many posts on the subject to get a feel for the employment market and your prospects. Do you feel lucky?