I'm sure it's been suggested already, but I'll add my voice. One thing I have really gotten used to (in DDO) is the ability to use a hotkey to cycle through interactable objects near me (chairs, chests, doors, etc.) and use another hotkey to trigger the interaction without having to actually mouse click on it. For example, I generally bind Q to cycle interactives and E to trigger interaction. This way I can steer using the mouse and WASD, then use Q and E to open the door in front of me without regard to where the mouse pointer is on the screen. It just feels that much more natural and immersive to me to not have to move the mouse around to accomplish such things.
I think this is the first time I've seen anybody mention key binding. One of Portalarium's goals is to make everything that seems like it should have a use usable. It seems to me that in a town, where there will be a ton of mugs, doors, chests, books, chairs, etc., you'll be punching Q a lot to finally select the door in front of you, but perhaps it won't be as tedious as I can imagine. In another game, I would constantly tap the "select next object" and "select next enemy" buttons as I ran across the landscape, so I would see things I might otherwise have missed.
Although I don't know how this will fit with the stated goal of not giving you in-game clues to people/quests/items. In other words, things might not identify as usable unless you actually try to use them. Just wondering about how this fits into that methodology.