I spent a couple of days in a psych ward, nothing serious though. I was only in for "suicidal ideation" (really, self-harm ideation, but they consider them one and the same), so I probably didn't see the half of it.

I think one of the biggest factors is how much of a danger you are to yourself or others. Implying you're suicidal is basically a ticket in there. Violence is probably also a way in, though you'd most likely be in jail first if said violence was against others.

Real psych hospitals might, I think I hears something online about "rubber rooms" or something. Again, that's only for truly violent, dangerous patients.

Pretty sure that's illegal now.

According to the internet, no. My mom;s been threatening to have me locked away for life but supposedly, that cannot be done unless it's a psychiatric criminal facility. But for someone who's merely depressed, functionally schizophrenic, etc...probably not.

Oh yes. Everything gets taken, documented, and put under lock and key. I wore the same underwear and hospital gown for the 2-3 days of my stay.

That depends entirely on where you are. When I was in I was the youngest person there by far. There was one old woman who used to yell a lot, but mostly people just lolled around, chatted occasionally. There was another individual who was terribly argumentative and scared the hell out of me, but this was just my experience. I didn't really talk to anyone personally.

I don't know because I wasn't there for long: and there wasn't much to do except eat, watch TV, sleep, and read from a pitiful collection of books. There was also therapy options, but I didn't care much for those.

Once again, how much they help depends on the person and the place. My brief stay was useless, I'm actually worse now, I think.

As to forensic patients vs. normal ones - I would guess the two are kept separate. There's no reason otherwise.