All three of my mandolins have pickups - so they are easy to plug in and play. I prefer a mic but I doubt that's an option with Deadheads.

As far as barr chords - I cheat a little bit. I often play a 2 fingered C chord { major and minor } with my ring finger and little finger and use my first finger to fret the low G string. Then I flatten my hand a little to mute the E string. That way I get D, E, F and G chords up the neck. I do play a full barr chord in the 2 fingered G position { major and minor } to get my A , A flat, B , B flats ect up the neck too.