While we didn't really thought about the Ren-mechas to have a 'sentient' operational system (More like a navigational system), I think we'll include it. ^.^ So yeah, feel free to have an OS-tan for your mecha, whatever you want to name it. I'll discuss things with Haruna later about the follow-up for this. The suit is, basically, like the suits from Date a Live. 

[hider=Click Here]
[IMG]http://www.entertainmentearth.com/images/AUTOIMAGES/BA81415lg.jpg[/IMG][/hider]

While the weapons won't look so heavy (As its main function is to canalize Renkai and use it as a weapon), it does differ in the fact that it has a 'visor' of sorts, with a HUD and your Navi. The mecha reacts to the implant, so yes, it can be summoned whenever you need it while in the city, thanks to the military underground facilities in which mechas are stored. For suiting up, feel free to come up with your own way to do it, as an exoskeleton of sorts, it attaches to the body via a direct link with the implant (Usually ubicated in the stomach), this is completely wireless. As for who she could work for, either for the military, the RIS or the IK and only the security staff is permitted to use them. For the IK, however, there are those in the project RMDW who are also allowed to have a Ren-mecha.

I don't see a real problem with the last part, just be aware that the real 'Magical Girls' (Gem-mancers) will practically hate her. She can either paint it herself or request the paint job.

Any more questions, feel free to shoot them out. ^.^