in wall wire wall plate?

That looks like very nice product for a very good price.

My only concern about it is the density of the connectors.

They are certainly too close together to use lugs, which I prefer. Bare wire ends could be used, but only if they are carefully formed into a question-mark shape and then tinned with solder, to prevent bare strands from shorting to an adjacent connector.

I guess I would use banana plugs to terminate the wires on both sides and plug them in. That would seem to be the easiest way to insure good connections and make sure there is no potential for shorting out.

Using banana plugs is also handy if you need to temporarily disconnect for vacuuming or realigning equipment.

I opt for no plate and simply stick the wires through the wall at the back of the surround or up through the floor; 100% hidden. I leave enough length in the wire to reach the receiver and finish the wires with banana plug ends for the receiver or crimp lugs for the speaker connectors. All wires are hidden in the wall and run under the house to come up through the floor behind the entertainment credenza.

I despise plates as utilitarian and unsightly.

If your speakerwires are hidden behind an A/V rack or stand you can also use these and avoid an additional banana connection (and they can be painted to match your wall color):

http://www.monoprice.com/products/product.asp?c_id=105&cp_id=10425&cs_id=1042509&p_id=3997&seq=1&format=1#largeimage

If the hole is the size of the cable, friction holds the cable in place and yes, once you add plug ends it becomes more difficult. One can also wrap tape around the cable ends to make the cable size larger than the cable hole in the wallboard. And if you must have a finished look, simply screw the finishing plate directly to the wallboard.