Yeah, the car insurance thing is a right malarky! Had a friend who had his premium increased when changed address to living on base vs parked in a street in the middle of sheffield...
He obviously inquired about this and was told "all those squaddies running around drunk on a friday night" or something to that effect were the reason for his increase.... despite being based at a certain countryside station somewhere in yorkshire, which has about as many squaddies as my parent's house.....
Agreed, hats off to any scally who will take the trouble to steal your car stereo from behind 10 feet of razor wire, cctv and live armed guards.....
As for the finance thing, fully agree, leave all your details as your parent's address, just don't bother changing it! When it comes to mortgage time, rather than just giving them your current level of pay, feel free to give them your pay scale and indicate whereabouts you are on it, how close you are to pay rise etc. Had no snags at all getting a 4.2x mortgage, although it helped that my financial chappy is ex-light blue also!