I have always thought wands were carried in wand cases, similar to scroll cases, carried on the belt, and easily accessible. You can use the quickdraw feat to draw a wand, so I would say they are quickdraw items.
As far as the holy symbol thing goes, per RAW I don't think you can use a holy symbol at the same time as your mace and shield. However, if the DM is flexible enough, there are ways around this. In one campaign, my cleric actually has his holy symbol mounted on the shield.