I use both - indoor and outdoor. Both can be safe and both can be dangerous. Sometimes at indoor I see all 8 - 9 lines occupied, so RSO cannot see everything the same time.. but there are cameras at each line.
Sometimes at outdoor range I’ve got classes or training sessions with 12 - 16 students. Can 2 or 3 Instructors see everything? Of course not.
So it is actually not about indoor / outdoor - everything is about how these are organized.
Talking about idiots - idiot indoor is usually separated from me by bullet-proof wall… which doesn’t exst outdoor.
I’ve been to a few indoor ranges, the smallest has 9 lanes, the biggest 20.
I feel safer with 20 in spite of having more people to deal with. Perhaps, I’m a bit claustrophobic in terms of space, not of the crowd. I like it on average non-busy days, we’re assigned one extra lane between shooters.
I’ll add “and action open” to that, and skip the 180 degrees part as I’m not sure of what your 0 degrees is, (90 off vertical, aka horizontal works for me) and agree with your “aimed downrange” even though that’s where I’m headed to check/change targets. I usually offset the rifle, aiming away from my path, as I keep hearing about “gun violence” and though I’ve never witnessed it, I’ve heard it’s a big thing.