Yeah, I agree, they were in a bit of a tricky spot at the beginning of the season since they weren't an official unit anymore until they got re-instated after that hostage mission in ep 1 of 2nd Gig.
Yup, Aramaki's so damned good
Yup, I guess there's no proof that everything in that "flashback" happened exactly like that but the Major seemed to know some of that story as she showed at the end of that ep so at least some of it seems to be "real".
Finale hint spoiler:
Yup, we keeping getting more hints that that's the case ever since that ep.
Yeah. Last episode confirmed their AI are in a joint Japanese and AE satellite at the request of the Major, and not in each unit when the Tachikomas opened each other up.