The broken vases are there mostly for atmosphere, though can be used for the first set of pressure plates. Later areas don't contain so many broken containers (the tutorial dungeon is an old tomb, that has been searched at least once already).
Yes, if there is an easy alternative, you should avoid using consumables (within reason).
When using the Active Search feature (on console, or using a controller on PC) or in the inventory, 'Toggle Info' gives information about the item. For a container, it will just show the AP cost to open it (if it contains any items) or will be blank (if opened and looted); for something like a shell, it will list the effect, if you've discovered that by eating one, the AP cost, duration of the effect and a description. Try it on scrolls and potions, etc, in your inventory.
