Marty's fatal flaws:
1) The god complex. Big enough to consolidate into a single line.
2) Always knows he's right. Especially when he is.
3) Fails to recognize "the opportune moment" when it arrives.
4) Kills when happy.
5) "I'm a lonely, insignificant speck on a has-been planet, orbited by a cold, indifferent sun."
I'd be much obliged if you'd drop me off at my ship.