I'm relativey new to the game and I've recently picked up a 2nd hand Callaway Razr X Black Driver which has some slight damage to the shaft as pictured below. Will this affect the integrity of the shaft at all? Also if it is only cosmetic, what is the best way to touch this up?
looks like a little bit of bag rub, can be quite common and will not affect the playing characteristics of the shaft. Have no idea how to touch up, personally would just leave it
agree with Fundy - if it's at the point the club will rub against the top of the bag then that's all it will be, possibly from someone not having the appropriate head cover (or keeping it fitted).
you could spray it with a protective clear acrylic but unless you know what you are doing it will probably end up looking worse that it started.