quest leveling etc.
u can get it all done
some1 else can play on your acc.. thats a thing yes
if u want some1 to do like your necromancy skill from 0-99 - then u can pay some1 to do it
just be sure its not a random if u have high value on your account - and take needed steps to secure your value in game
suggest using a mediator if u dont know ppl around this rs3 forum and its your first service ever