Anytime I start a new character I usually predefine what type of person (s)he is going to be, like sometimes I'll want to play as a savage murderer or a great thief who's Karma I always expect to be below neutral. But this is never the case, maybe I just can't get into the RP aspect of the game even with the backstory and everything, I always end up being neutral. My actions in game tend to reflect those of my real-life self which would appear to be a bit of a grey-do-gooder.

Does anyone else's own thoughts and ideas get in the way of a good RP and does your karma level reflect who you are as a person in RL ?

A lot of times, my initial playthrough is less as a character and more as myself. In that occasion, my in-game karma reflects what I believe in the real world. Otherwise, I don't concern myself with karma. Just do what the character would do.