Got a bit more done, the low panel is pic 3 is also cut out now.
Started cutting the rivets in the ceiling but my arms turned to noodles no it's gonna have to wait til another day.
To sum up where I'm at: seats are demo'd, all upper wall panels down, right side lower panels out except a small one, first ceiling panel is ~30% down.
Run into 2 types of rivets, really easy to grind off the ones that only go through a single panel, the ones through double panels are WAYYY beefier. Tried drilling, eff that, grinding disc worked pretty good, flap wheel worked pretty good, might fire up my bigger grinder to knock out the ceiling, 4.5" dewalt ain't cutting fast enough for my liking.