0-level spells at will is in my opinion a great idea and a way to give spellcasters a good but not unbalancing boost at low levels. It should stay as it is. There are of course a few problems with some 0-level spells with the current wordings and these should be worked out. But come on; it makes perfect sense for a wizard to be able to tell whether there is magic in the area or not as a standard and re-usable ability. Ther are many ways to fix any problems, and perhaps this will encourage DMs to be more inventive when it comes to magical traps and effects.