Woody,
you have received plenty of advice... Let me simplify if I may..

The tuner has to sit within reach usually, so that means the end of
the long wire drops down into the shack to the tuner, no coax
involved... No baluns, etc. are needed or advised...

On certain bands the case of the antenna tuner is likely to bite you
when you touch it and the rig also The cure for this is to run a
quarter wave radial for each band from the ground terminal of the
tuner... These can be run around in the room, or exit out the window
and fan out on the ground can be slit into the dirt, whatever
MFJ actually makes a tuner for the ground radials.. Works quite
well...

The purpose of the ground radial is to act as a counterpoise for the
antenna currents reduces ground current losses and to move the RF
peak voltage out to the end of the quarter wave radial leaving the
tuner/radio at low RF potential...

Don't over analyze this... Just hang your longwire, put out your
ground radials, and have fun on the bands...

denny / k8do