Glare is a problem with certain sun angles, but it depends on your eye height relative to the level of the fairing top. Specular reflection is relatively unaffected by scratching. The only way I could get around it, (particularly bad in fall and spring) was to smear auto paste polish on the part of the fairing that bounced the sunlight and not wipe it off. The white smear dramatically reduced the glare. I also noticed there was a current of air that blew over the top of the fairing and curved down and followed the inside of the fairing out to ground level. Saw several leaves follow that path before I figured it out. Fairing weight will be noticeable on hills, such as multi mile uphills in Colorado. They do scratch easily but if the scratches are not very deep it is easy to polish them out. My fairing (Rotator pursuit) was much longer than yours is likely to be and owing to the pedal position and curve of the fairing, low speed turns could result in the fairing hitting my feet. They were warmer (feet and legs) in cool weather. Bumpy roads resulted a booming vibration in the fairing, somewhat noisy; ditto at high speeds. OTOH when I had the fairing on even other bents couldn't draft behind me, there is no pocket of dead air, and I noticed no difference sitting in behind a DF rider or riding along side: the fairing was equivalent to a permanent DF draft. The few high speed down hills I did with and later without the fairing showed less difference than expected, a hill where I hit 37 with the DF, 39 with the unfaired bent was ... 39 with the fairing. It may be that unexpected vortices suck the advantage out at higher speeds. Finally fairings are speed benefits only if you habitually travel above about 17mph, but they really shine above 20mph. You and Stamfap (?) a British poster on over 50 group, seem to have a similar attitude toward weather. He goes out on an ATB tandem for 6hr rides in intermittent rain and sleet. You have to deal with road spray off the tires before the fairing will help in the wet. Rooster tails that escape the tire and fairing with still get you in the face or back.
Steve