RE: does fuel choice effect flight time?
I have a NexStar and I get more minutes through throttle control. Not always running wide open. I use 15% nitro. I always run a little on the rich side to extend the life of the engine, and in hot weather I don't want to run too lean either. My struggle in the beginning was the engine cutting out during flight and it wasn't until one of the more experienced pilots set the low speed setting to correct that. Also, I switched to APC 12.25 x 3.75 after 3 or 4 tanks.
I know a lot of more experienced pilots who are always willling to share their knowledge. Yes, I started with a RTF and an instructor with a buddy box. My instrctor had me take off all the extra features - air brakes and anti stall stuff. But I was flying right away and learning more of the details of flight, repairs and construction as I went along. My instructor would advise me how to do the repairs and help me more if I needed. I didn't feel as bad when I got a few dings and dents in my trainer because it was repairable and replaceable. I would have been a lot more devastated if I spent months building from a kit. Times have changed. So learn to fly first and learn to build later. Being able to have early success means more patience and future successes in the long run.
I fly out of Michigan Signal Seekers field in Westland, MI.