Great post KC and I think you pretty much nailed it. 
Elvis Presley Blues has never been a real favorite of mine. I mean GPN nails it and as my wife said after the last Atlanta show "I don't like that song but that was good.. the three acoustic guitars working together was beautiful". 

"Paint It Black" always starts off really really good but never, I don't know, never gets over the hump so to speak. "Gimme Shelter" based on the video I saw from last weekend was good, real good. 

The Beyonce cover is incredible, lot of energy and character association in the performance. Wonderful.

"Black Hole Son": since this started popping up I wondered if they are going to be covering this for compiltation CD or something, you know like the "Tush" cover for the ZZ Top Tribute. They have a history of practicing some songs before they get recorded. It is an ok cover, probably resonates with a younger demographic than myself.

"Pain In My Heart": wow. They performed this last year here in Macon, Ga. Otis Redding's hometown. Just freaking incredible. Doesn't need to be a regular but for sure mix it in for those special occasions. 

"Crazy On You": does showcase Benny's incredible talents and I think Grace nails the vocals. Good to keep in the mix.

Suggestions:
Led Zeppelin's "Babe I'm Gonna Leave You"
http://www.youtube.com/watch?v=rrVDViSlsSM

Eagles:Those Shoes"
http://www.youtube.com/watch?v=_ywfnnCBERY

Donna Summer: "Sunset People" take it and noc it up... 
http://www.youtube.com/watch?v=adyMcfZr7Ew

looking forward to see some other suggestions.