I'm with you on all counts.

I agree. I usually give a little test jiggle at first, not a full-on attempt to open it. The test jiggle should signal to the person to speak up if the door is unlocked.

Yeah, I try the door--open slowly. Actually the "knock" respect is pretty low on my list--I might even ask "anyone in there?" before rapping on the thing.

knock reaction.

Another open door slowly person here.

I usually just pee through the keyhole.

I usually give a little test jiggle at first, not a full-on attempt to open it.

I do this, but then I worry that perhaps the restroom is unoccupied and it's just a sticky doorknob/door. So then I try again with more force and I worry I'm freaking out the person in there.

If I'm in there, I appreciate when someone knocks. I just say "OCCUPIED" and they leave me alone. No need for a conversation. If they jiggle the handle it makes me worried that I forgot to lock it (or the lock doesn't work) and they're going to barge in.

It's already a vulnerable enough position to be in, and now I'm supposed to converse with a stranger?

No, you're expected to yell "Oi!" or "Hey!" or make your presence known some other way, and that's that. Trying the handle without warning is pretty douchey in my book.

This is why you're supposed to sing or whistle while at commode.

I can honestly say that neither hearing someone knock or try a handle while I'm on the toilet is enough to make my day even the tiniest bit worse. Y'all worry too much.

i have no problem yelling "Occupied. What you wanna come in anyway? Too bad, drunky."
i also knock, call and check with a jiggle, whatever, because if you have to get a key or a person, it'd be nice to not have a shy pisser on the other side.
Public bathroom, not private rest room, move along.
Hey, i'm "considerate" of the many reasons someone is taking up bathroom time, but maybe it's not the best place to call a "line up" in a busy place on a weekend?

It's like the tried and true club saying, "If you can't take a shit before a show, you've got bigger problems."
Still, not my problem.
Move it along.

i've had friends with such profound bladder shyness they have passed out rather tha peeing. Still, not an issue you want to work on Saturday night.

OMG Bunny Public Restroom!!

Test and then leave it alone. I HATE when people knock after they realize they can't get in!

I knock first, listen, then try the door handle. Once I'm inside, if it's possible, I'll run the cold water so someone outside will hear noise. If someone knocks, I just yell "I'll be out in a minute."