'UBHC17J14SHH and according to the on line documentation it says it is a
single circuit system. Does it sound like we are dealing with people who
don't know what they are doing? Should we call a RUUD dealer and pay for
a different service call? '

Yes, its best to use a RUUD/RHEEM dealer.

'
The heat coming from the vents is luke warm. I have never lived in a
house with electric heater type furnace so don't know what is correct
but would think the output would be greater than luke warm.'

You should be getting close to a 45-50 f. rise thru the furnace if its
working correctly...after approx. 2 minutes of it running which gives
the furnace enough time to stage on the elements ; (that is, the
temperature of the air coming out of a nearby register versus the air
going into the furnace (return). ).

'I know the AC guys don't like AHC (American Home Shield) '

These Warranty Companies are wrought with problems ; usually, they send
people out who havent a clue what theyre doing. Call a RUUD/RHEEM
dealer. Ive put in about 15-20 of these RHEEM Electric Furnaces and ive
had problems with a few of them within one year of installation. Usually
the sequencers or the limit switch(s). I like the stainless steel
heating elements wrapped around the inside of the blower housing though
-- better than the cheap nickel chromium wire looped back and forth like
a giant toaster.