Shamrock
AFCO is the Armed Forces Career Office - they will at least have a leaflet even if the bloke in the chair doesn't know the detail himself. But...
1. You will directly apply for ATC. Flight Ops is a different branch entirely. There are age limits but the RAF website or AFCO will tell you what they are. IMHO I don't think you're too old yet, but you haven't got long to play with.
2. You will be required to apply at the AFCO, which will take several months, then attend the Officers and Aircrew Selection Centre at Cranwell to do up to 3 days of selection tests including the one for ATC. After that you'll wait for a vacancy. Next you do Initial Officer Training ( about 4 months I think), followed fairly promptly by JATCC - the Joint Air Traffic Controllers Course, which I think is about 9-12 months long now.
3. Pay is pretty meagre to begin with, but when you reach Flight Lieutenant (automatically), your salary with be in the 30-40s. An ATC tower can be a bit of a back-stabbing place because there's an undue concentration of commissioned officers all vying to get on. If you get there you'll see. Promotion is arguably on merit an you will be required to rotationally do 4-month detachments to wherever we have ATC officers - Falklands, Balkans, Gulf etc.
4. In the RAF you will work civilian aircraft and are granted permission by the CAA. However, when you leave the RAF you have no licences whatsoever, so you're just as qualified as the next guy. I have heard some people say their licences cost them 30-40k when they left and, of course, age is an issue for CAA selection. In summary, if you're going to join the RAF as ATC at your age, I wouldn't think it was a tremendous route to the civil world.
As for you not being eligible for Eurocontrol because of personal reasons, if this is a nationality issue you need to be British to join the British Forces. If shamrock is a clue, you won't get in.