Interesting!
First questions first..a girlfriend of 10yrs that doesn't an RAF life style...so you prepared to forget the life style?
Your second point, re climbing etc, may well stand you in good stead if,when you get to a front line SAR unit, however, you may have to prove yourself to get there and 'hoop jump' in the SH world for a number of years prior to being considerd.
Your age is not levant, up to a point, if you are physically fit enough to do the job.
Corners are not cut. Rest assured you will have sound and safe training.
Others out there will be able to offer better advice than me, and I would advice you to take it all in, but in conclusion I can highly recommend the road you wish to follow. G