Fella if you want to join then join, you seem keen enough i would advise living life a bit more but its your choice, i had a choice i was gona travel and work in states for a while or join the corps, guess which i chose!
Havnt regreted it, i work at Lympshvitz (Commando Training Centre) if you want any phamphlets or info let me know, PM me your address and i can drop em off i live in Plymouth aswell, your dad still probably has connections in the corps (you never realy leave the family) though you could get most of it from carears office just make sure you see a Bootneck and not some crusty old matlow that dosnt have a clue what hes on about they will tell you any old shit, and give you all the wrong advice.I will be able to tell you exactley what the PRMC comprises of, If i can be necky as well can i give you a card, if you do decide to join i will get a recruiting bounty if you pass week 15.
Dont worry to much about your age the corps will mature you very rapidly, i have seen perce recruits and they act like 16 year old dickheads hanground in gangs on corners being nobbers your average 16 year old RM recruit acts completley diffrent