Sir Dante is required for the duke's murder quest, but after that I don't think he is needed. You could just take over the house with him there. It is never available for sale, though you could kill him (I assume - some essential NPCs can not be killed), or maybe turn into a spider and chased him out (don't know if/how fast he would return).
There are all kinds of roomy places close to teleporter pads. After freeing Zandalor, I took over the back of the council hall. You can pile chests around a teleporter pad in the open, but might have NPCs or animals wandering around getting in your way.
