Thanks for all the good comments and advice. I counted my rpm today, I was a bit surprised it was so low, about 50-65. I lowered a gear and got 80. When I first started riding a couple of weeks ago I pedaled some at that speed but thought it was over pedaling, too much spent energy, and went up a gear. Today I saw the difference and stayed at 80 a lot more. I can see the difference it made on my legs. I rode seven miles in one hour on almost flat ground. I ride at a casual pace. Which made me wonder about the speed/rpm balance. If I want to ride at a slower speed I would drop a gear to keep up the rpm, true? The speed I was going in third gear at 80 rpm was faster than I wanted to go. I have nothing against going faster but I like the laid-back slower pace. I hike at a laid-back slower pace to, it's my style.
I bought some glucosamine today. I am going to work on a strengthening routine, riding, squats, and nutrition.
I think I solved the slipping seat problem like I said. It didn't slip at all today. I am still going to look into a better QR or regular bolt though. I figure it can't hurt to have a back-up.