I know you don't want to hear it but you NEED to fix and fly the trainer, probably for most of the summer. Put the gear on with nylon screws so they will break instead of ripping out the belly of the plane. NASA flies T-38's, saw lots of them when I lived in Houston, of course I can't tell you that was a NASA plane but it looked like a T-38.
Don't know what Stik-n-Rdr was talking about when he said full size pilots found using the rudder was un-natural but I doubt he knew what he was saying either. Something you pick up in just a few hours of training and get better as you go of course, like anything else in flying. Un-natural, give me a break.