In Gothic 3, there's only one 'use' button. Using an anvil or alchemist's lab will open up your profession window. Using a lootable object (corpse, flower, dropped item, chest) will loot that object. If there's more than one item to pick up, it will open the loot window, your inventory, and a 'take all' button, so you can take one or more objects from the chest/corpse.
But what about locked chests? Pressing the 'use' button will automatically pull out a lock pick, and you'll attempt to pick the box. You know in advance if it's locked or not (red names are locked, orange are unlooted, white are looted), so you can make your decision in advance of whether or not you want to use a lockpick on it.
Are there keys? If there are keys, then which is used first, a key or a lockpick? I would assume keys have specific uses (for hard locked doors, like armory doors and kings' quarters and whatnot).
Automatic use is great because it's a fairly accurate simulation of humans' speed. In a system where you have to open your inventory, equip a lockpick (or key), then use the locked chest, a lot of time is consumed. It breaks immersion and is tedious. I am a firm believer in the idea that anything a player can do in an easy-yet-tedious way, should be given to the player in a difficult-yet-simple way. Instead of making a player open up their inventory to equip a lockpick or key, have a box pop up when you try to open a locked chest with a number of large buttons. One with a thief's tools, which says "Use lockpick (6 in inventory)" and possible other options being: "Use skeleton key (2 in inventory)," and "Use key to king's bedroom (1 in inventory)." This would allow players the options of an "equip -> use" without the slow, tedious, immersion-breaking UI.
Over all, I feel automatic actions are more intuitive. Or is my character really so stupid that he can't figure out he's supposed to use a lockpick on a locked chest?