I knew nothing of the Vampire Lord. Where did you guys find the inside info, as I want to read it as well.
Anyways, I guess if you inventory is full you can't pick it up. Personally, I feel the inventory could use back up spots, this way you can carry items and switch them into hot slots *hot key useable slots) when appropriate. I think this is useful, as later on I would like to see better item drops, but maybe that is just me.
You could always have ctrl+click mean used instantly. Or perhaps it is instantly used