I don't see the slightest body suit look at all. She looks more like something made of hi-tech plastics or other materials. Kind of a 'sexy robot' look.

: but the main thing that stands out is that it gives her a
: somewhat forerunner/promethean look with some small metallic pieces
: floating on it.

There's a chest disc and a neck band, but I can't quite see them closely enough to be sure if they're floating or whether they're attached. Can't say I get much of a Forerunner/Promethean vibe, if any. To me this could just be a straightforward revision of her original appearance - although she looks prety solid, rather than tenuously holographic.

: All in All the redesign for Halo 5 makes sense just based
: on her changed allegiance.

A redesign from the weird and incongruous naked look of H4 made sense regardless of changed allegiance. She looks massively better here.

: If anything Cortana keeps people off
: balance by being sassy and outsmarting pretty much anybody or anything.

Keeps people off balance? I assume you're alluding to O' Connor saying "she does it to put people off". Why is Cortana suddenly being ascribed with this shallow and petty attribute? I don't see her like that at all.

: Best example, is when she confront 343 genocidal lightbulb in Halo:CE and
: mixes her extensive knowledge with some good old fashioned insults

Although, "sod off" always did sound hilariously wrong for the American voicing. She kind of blew it there.