I have plans for something like that... >100% agreed.- Empty wilderness areas between quest locations like there was in BG1. That was one of the biggest disappointments for me in BG2.
- The spelljammer ships should've been more than decorative. ie) I agree with the lack of extraplanar travel.
Most under-used idea: a non-mage opponent(!!!!!)
Remember the acid kensai? i liked that ALLOT, and it kind of got me thinking...
How about a pickpocket who basically robbed the PC and his/her party blind.
The thief could would only 'attack' in the city area, it would spawn out of sight of any of the player-party and would hide, then move upto a randomly chosen member of the player-party and pickpocket them, then run off.
If it's revealed before it gets to pick anyones pocket it would have floating text like 'Ack! Discovered!?' and run off.
Note: By 'run off' i mean leave the map, via an exit point.
If the Thief mannages to pick pocket a character it would say something like 'Haha, it's mine now' or 'yoink'... you get the idea. The theif would then run off (all the time being a light-blue circle and unhostile character. If the Player realises what was going on and attacked the theif, the theif would become hostile and fight back, but run if things started to look grim.
Any items stolen by the theif, and in it's possession when it leaves the map would be put in the theif's 'stash' this would be a fairly ordinary container hidden in the bridge district for example which could only be opened with the use a of key, which the theif carries around with him/her.
The thief would spawn everytime the player entered a city-zone with the exception of one, which would be the area where the thief's stash was hidden. The theif wouldn't spawn because he's too busy standing infront of the container that he stashes his gear in, and talking to himself about how smart he/she is. when the theif spots the player-party it would realise that it's stash has been found and would attack the player-party to the death (no more running at the 1st sign of trouble).
So... this thief could be anything from a simple level 10 theif to some kind of bounty-hunter/mage 24/25 beast. Anything you want could trigger the thief to start stealing from the player-party. No real reason to it at all... but if the thief was made into a power-player character it might count as a tactical encounter, imagine fighting kurosian if he stole the celestial fury off you, and you had to track him down to recover it, anyway I'm just repeating myself now - happens when i'm tired... so... er... meh just a random idea.