RE: Are all trainers trikes?
I had a '70 Plymouth Valient. Three on the tree, armstrong power stearing, armstrong power clutch and brake. The air conditioner worked by rolling down the window (yes, you had to crank it back then). I don't see too much difficulty with a taildragger, but it was a little awkward at first with my Slow Poke. I guess the manual transmissions helped.
NorfolkSouthern