Oh, how I know what you mean about not looking forward to walks and stuff! I have always had those sort of problems with Bob, picking up things and eating them, and at one point I considered the muzzle too but over the last year or so he has eased up on it a bit. He still will get a frisbee etc if it is thrown for another dog when it comes close (I keep him on the leash so I can keep clear a lot of the time), golf balls, and any other sort of ball too! He just will not give them back without some sort of struggle. If it is a large enough item, that I can grip it without going in his mouth, we play the waiting game, I hold his collar with one hand and the object with the other, sometimes he gives it up fairly easily but there are other times when it takes ages and I feel very foolish standing there! Small things are a different matter, I used to go into his mouth and get it until one day he shifted for a better grip and in doing so bit me, I use give/treat method now, but it doesn`t always work which is a real worry. Using the Gentle Leader as slleipner suggested may work, I use one when we walk into town or go out somewhere where there may be a few people and it works well. It has to be used correctly though because misuse can harm, like any other aid I suppose. I have thought of going to a behaviourist too, but I really cannot afford to do so, I can just about cope with his antics as they are at the moment, though it would be nice not to have to!.
I am sorry that I can only empathise and not have anything positive to suggest. I truly hope you can find some way that works for Kia, she is such a beautiful girl. Good Luck