[@Howler] I know you're still working on your character, but I [i]do[/i] have a few notes to make about it.

To be frank, Trent sounds like a sociopath. He gets way too much special treatment for an apparently not-very-well-liked guy.There is no reason why a star rookie with an 'average' performance rate would be assigned a special machine. If his heart wasn't in it, and that much was clear, he'd more likely be pulled out and assigned to a new unit rather than given his own special machine. I'm overall not a huge fan of the apathetic-mechanical-loner vibe I'm getting from him. 

In regards to your machine, I failed to mention this, but I prefer that most machines are able to run without the necessity of an external power core. Also, nimble/aerodynamic, and external power cores don't mix. External power cores look like:
[hider=Power Pack][IMG]http://i62.tinypic.com/6pw8b9.jpg[/IMG][/hider]

Plasma weapons are also 7 weight and [i]9 power[/i] now, because of their power.

Also, keep in mind than an Ultra Light MAS is essentially an exoskeleton, and are primarily designed for infantry support instead of MAS combat. 
[hider=for example][IMG]http://i57.tinypic.com/2607j8m.jpg[/IMG][/hider]
Mounting a gatling gun on the unit's head would mean attaching a minigun to your helmet. It'd be more likely to have a LMG or HMG attached to a shoulder rather than a minigun. 

Experimental generators are also uncommon on Ultra Light's but I assume this is a prototype unit, and I never made any explicit rule against it.