What is the most economical way for me to put a motor on my own bicycle, without being a bike mechanic.
You may wish to check out my list of
ebike kits:
Avoid front hubs on an Aluminum fork! Use a magnate to test it.
About the weight on your present bike, find out what kind of batteries it has. If they are Sealed Lead Acid (SLAs) you can cut the weight by half by using a lighter, and more expensive battery. You may also get a marginal improvement in performance.
I use a helmet mirror with a handlebar mirror mounted upside down, it drops below the handlebar. Otherwise, I am trying to look through my arm to see behind me. You can use a mirror that mounts to the end of the handlebar, but you will probably break it if the bike falls over.
Glad to hear you have discovered ebikes.