Dude tells me the room, I click on the door, and it just says it looks interesting. What obvious thing am I missing?

Have you tried lockpicking it? (right Ctrl+click)

Usually, when the interface shows "seems interesting", you have to use a character's special ability.

Thanks, i'll try that tonight. Too used to having my hand held in RPGs these days lol.

Was stuck at the same place. Is it me, or did they fail to explain that anywhere?

Using the picklock and coming across this kind of situation was the part of the very first quest in the game.

Yeah they explain how to open doors like that as the first mission in the game, where you get the camera and your money.

It's very forgettable though, the ctrl-click thing is a bit weird.
This counts double for some other skills that don't get the "this looks interesting"-bit.

However in Franks Flophouse, there is a door that can be opened only with the upgraded lockpick. But you'll realize that once you cannot open it.
I don't really get why you got stuck as there is both a top level and normal level lock at the beginning og the game at Rowdy's.