I can remove default verbs with objects. Rooms have the default verbs of objects, but I can't remove their verbs, or make them hidden.

Edit: for better context, I mean to say that I put rooms inside rooms that can be entered (for example a hallway) through the compass exit ways. Is there a better workaround than moving entire rooms to limbo?

To Quest, there is no difference between an object and a room. If the player is inside it, it's treated like a room; otherwise it's treated like an object.

On the first tab of a new object/room, there is a drop down to select if it is an object, room, or both. This controls which tabs are displayed in the editor. If the room is inside another room that the player can enter, I'd suggest setting its type to "Object and/or room" - that way, the editor will show the necessary tabs so that you can change its verbs and similar.

I'd suggest giving rooms an "enter" verb which moves the player into them; because players are likely to try typing that.