If you get your degree before you join you will start at Flying Officer, the green shield route stopped some time ago, but you will only do a couple of years as an FO. Time well spent avoiding responsibility. And you will probably be a flt lt by the time you finish training.
As far as getting an in-service degree, the blanket stackers etc get buckets of credits in the training system and then can get the degree in a coupe of years after starting productive service. As aircrew do not bank on it.
A BS gets it all done and then does a modicum of OTJ. The aircrew qualify, convert, become operational, blink and start again to pass the annual standards checks. In between you are either on route, out of area, or detached to Cyprus or Red Flag.
If your feet touch the ground it will be in the bar with a tinny.