A tank should be able to solo mobs even at high floors, although some of them have gimmicks and some will still punch your face in if you don't have Steel on, so guess he took it too carelessly. That said people can rez at least in parties. PotD is deceptively hard once you get to high floors though, even in a party. While solo is obviously hard, some mechanics actually get worse with other people ironically so you have to be careful about what you do.
As for doing savage blind without listening to his party, that's definitely dumb as shit but he's probably aware of it by now. Works fine in ARR because the difficulty was just not the same and it was also nerfed over time due to inherent class buffs and stuff, so you can definitely do Coil blind since the mechanics are simple and the checks are easy. Alexander though that shit started the actual raiding systems, a lot of the mechanics are complex enough they're still used nowadays in various ways. It'd be doable as mentionned if he went at it like the other guys do, checking vods and discussing strats and stuff, or by just reading a quick guide, but blind without a good graps of how the mechanics work, yeah that's gonna be rough.
