If I apply poison to a dagger will it be useful for more than one stab?
Also can I equip the poison in one hand and a dagger in the other and "quick apply" poison to the dagger without having to go into a menu?
If I apply poison to arrows does it apply to the whole quiver or just one arrow?

If it's like Oblivion, then it's just a 1-hit, 1-shot ordeal.