yeah
the same guy who voiced Gabriel voiced a fish man literally named John Shoelace

Isn't the Pressure shopkeeper called Sebastian Solace

maybe
idk

https://pressure.fandom.com/wiki/Sebastian_Solace

Ah

fun fact: a-60 is a secret monster in pressur that can actually kill you

Yeah
Well technically
It's called the multi-monster, and according to devs, they are only going to use the design for this update
Additionally the rooms from Doors and Rooms have been found on rare occasions

Ik I read a comment on an 8-bit Ryan video saying there's a lot of reference rooms

There's a lot of references to a lot of things
you can find the Flesh Prison from ULTRAKILL
The Gummy Flashlight
Those little useless items in drawers you find in Doors

These 2 are voiced by the same person lmao

have they ever said....you insignificant f**k?

idk but sebastian is snarky as hell

ok

"*chuckle* I heard your head pop allllllll the way from here." -- Sebastian after you die to the Prisoner Swimming Gear

He also voices several characters in furry nsfw games,

Source: became a huge meme in the Ultrakill subreddit.