Help from DMs please?

I have made an error with my players and I am not sure how to fix it, because I had a headache and was not paying as close of attention as I should have been …

2 of my players have been playing since the cradle, I have been playing this game for 8 years … so it's fair to say they know things I don’t which can be a little frustrating. Most of those things I over-come by telling them they are in MY world now and the normal rules do not always apply. (Like Drow aren't always evil etc)

The party consists of: An Elf-Ranger, a Halfling-Thief, a Gnome-Bard, a Dwarf-Cleric, and a Human-Fighter.

Here is my problem: They found a wand of cure light wounds, I did not realize the Elf-Ranger snatched it. As far as I know he cannot use it, this player is not the sort to spend the points to take cc skills. Normally this is something I would ignore and let them work out themselves, but a couple players have come to me bitching. He may be planning to spend the points to get UMD … but since they found the wand they have not leveled so he has not had the chance to do so. Wouldn't it make more sense that the rogue (who does have UMD) or the cleric has that wand? Not having access to their character sheets right now I am not sure what to do, I would like to have a satisfactory solution to this issue before we play Saturday.

They (stupidly) let the CN rogue carry party treasure and I know the rogue is planning to pilfer some of the gems they have found and go on a shopping spree with the cleric. Sigh, I would prefer to avoid that sort of chaos in my dining room since I know it will result in a huge argument. I suggested to the rogue he simply steal the wand from the ranger and slip it to the cleric (something he could easily do) … but he said no. Someone help please, what would you do in this situation? (Other than not get into it in the first place)