First of all, this is just to help you more than anything, [sub][sub][sub]Mostly[/sub][/sub][/sub]retsupurae yahtsee said:snip
You haven't exactly said what your augments are, just that he decided to stay short and that he has some, nothing really even suggesting your capabilities. If you're still trying to decide what it is, disregard this. If not, you may start being called G.S.(you start pulling special new things out of you ass, more or less), but since you're new here, I'll give you the benefit of the doubt.
Just a warning, you may want to just say he constantly puts on a new coat of the blood(or he's extracted the essence of the tetanus) on the sword, because,and this is just me, I'd have your sword break within a few swings because you specifically said it was old and rusted.
You say he has poor hand-eye coordination, yet he has two guns for two different situations....
And to(maybe) help you with the aliens on the planet thing, you could change it to he was a part of a hierarchy where he was on one of the bottom rungs on a planet where the humans had adapted to a low gravity field and walked around in machines, which they also made into powerful weapons of war, which made a revolution very hard until your guy got his hands on the Hierarchs tech and sold it to the revolutionaries, which made him rich.
He then got his augments and was riding high for a bit before it all came crashing down(interest rates, money became worthless, adept burglars,etc.) because the new regime had no idea how to run a government and the old regime had either gotten off-world because they saw their impending doom and the ones that either stayed or were unable to leave were executed.