Agbsave9, Decrypt9, and Hourglass9 can all be used to export gba VC saves, though the first one is for the most part depreciated. After exporting the save you should be able to import it into VBA as a battery file and monkey around with it how you like (such as, say, using all items cheats or the like), then re-export it. You may need a save file trimmer if the sizes don't match up to properly re-import. On the second note, yes, it should be pretty simple since I've done the same on VBA, and is far less a hassle than the gba games, let me tell you.