I have flown a PTS. The RTF version and the only mod we did was to remove the speed brakes. I live at 5000 foot elevation and it flew fine with the 3 blade prop. I would agree that it is easy to lose orientation due to the coloring of the thing. I would put some striping on it to make it easier to tell up from down. The RTF is a nice package if someone is getting into the hobby due to the relative low cost. A computer 6 channel radio, 5 servos, engine, airframe, sim and buddy cord for 400 bucks. Most other RTF trainer packages are 300 plus with a LA engine [

], and a cheap analog 4 channel. The PTS ARF is only 119 bucks, thats what a SIG LT 40 costs. All ARFs have some issues that need fixing even if its just some extra glue. Also hard landings tear gear out of high wing trainers too.
I have never really flown a " high wing trainer ". The closest thing was a SPAD I made, but it had a semi symmetrical wing with no dihedral, plus it was a tail dragger. It was a point and fly plane, not self correcting at all. Then on to the Mach II and a Super Stick 60 with a .91 FS.
I flew real planes first. It only helps with understanding the principles of flight. R/C is way different.
I would definitely say that using a Sim really helped me. Best 200 bucks I ever spent on this hobby! I must have crashed 40k in airplanes by now
READ READ READ Thats the best advice I can give you Tankie. You will never get enough info, but the more you can the less mistakes and less money you will spend for those mistakes
Really try to find a club or some guys that fly that you can learn from. I met a guy at work and I bounce things off him all the time. He let me buddy box his SIG Senior once and then I was on my own.
Good Luck!