Clique/Grid? per MiRai's vid

Getting ready to set this up and had a question with regard to MiRai's video when he suggests shifting to a blank button bar on his healer and a Clique question:

1. How does the healer cast combat spells with the button bar blank? I'm currently using ISBoxer with the menu overlay grid on top of the action bar via standard 'wizard' config but, plan to switch to pro-config in future.

2. If I use middle mouse button for Clique (roll/press/side) for heal spells, can that button be bound for other things when it's not hovering over grid? i.e. middle mouse is currently bound to esc to close all windows/open wow menu, I'd like to retain that but when hovered over grid, does clique differentiate when to use certain bindings? I've never used Clique.

TIA