Hi Ageary.

Welcome to multi-boxing

As far as the issue with your paladin running to mobs which prevents your priest from nuking - dont worry too much about it. If you have 2-3 mobs on your paladin (or even just one) you wont be interrupted too much. You'll be unable to cast initially when charging the mobs. But when you've planted yourself and start whackin/concecrating - u'll be able to nuke away with ur priest. I 5 - box and I use a Paladin + Priest + 3 DPSers so I know where you're coming from.

When just grinding, use this sequence:

/castsequence Smite, Shoot

If you only keep on nuking with ur priest - u'll run out of mana pretty fast.

As far as looting, since I also use the Nostromo N52, I just position the mouse cursor a little bit right of my priest who is on autofollow (in your case on your laptop). Then I have the N52 software create a macro to keep repeating a Right Click macro. So all I have to do is walk over the corpse and it'll loot for me. You can normally kill mobs you're facing and usually the cursor is already on top of them. Set your interface on Auto Loot and you're money.

Hope this helps. Keep on truckin'