A lot of great advice here!! I too am in the same position. Last season I ended up with a concussion and whiplash a couple times on a flat down box. But by the end of the season I was attempting to backside board lower rails and doing them on boxes. For some reason I find back boards less scary on rails than 50/50's
This year I found it really hard to hit jib features and feel I am not as good/brave this season in jibbing (not that I was any good before). I am training for next year already for my core and balance so lets hope I find my balls by then to put it to use.
FYI I am 36