Give it a go pal. Be surpised if it worked, given that the carb models are built the same and the heat soak from the downpipes doesn't have much of an effect on it. The colour of the radiator is neither here nor there. It's pretty much firmly accepted now that black doesn't soak up heat at all and white doesn't reflect heat either. They DO soak up and reflect LIGHT and the old assumption was that that had some effect on temp. Simple experiments with cars have proved that a white car and a black car left out on a hot sunny day, maintain the same internal temperature.
Exhaust wrap is easily found and fitted. It's also ugly, soaks up salty water and when the water evaporates off, it just leaves the salt snuggled up to your downpipes. If they're decent quality stainless, shouldn't matter too much.
The guard idea doesn't ring my bell too loud. It sounds like a light metal plate across the front of the downpipes (unless I'm misunderstanding), if it is the case though, won't t that simply block airflow through the downpipes and across the front of the engine block? If so won't that cause a pretty sharp, localised heat sink against the engine block itself? If so, and bearing in mind that the front of the engine block is actually about 30-36% of the outer wall of the cooling sleeve for the whole engine (and the one with the most airflow) isn't that likely to simply heat up the water that you're trying to keep cool. I doubt it would be dangerous, but will it achieve the desired end? From experience, blocking airflow across the rad or the front of the engine isn't particularly desirable
Don't forget though, that Honda KNEW that the infected bike would run hot and that's why when they redesigned the XX to be infected, they also redesigned the cooling system as well. The rad is different and the oil cooler is bigger. In other words, they designed the oil cooler to protect oil viscosity (because they knew that it's life was about to become very warm) and the radiator/downpipes/ engine front were all designed to disipate heat through the airflow they have available.
BUT... (and dramatically saving the best and most obvious to last
) Honda knew your bike would HAVE to run hot because they took away more than 50% of the engine's cool air supply when the fitted ram air. The air flow through the nose inlets of the infected XX, is piped to the airbox to raise pressure there and increase the performance of the bike. On the carb models, the air through the nose inlets is guided (by a beautifully shaped plastic plate) straight down onto the oil cooler and radiator... and at 30, 50 or 100+ MPH that's a shed full of luvly cool air keeping my angel fresh and beautiful, whilst your bike is having all that air rammed down her throat in a desperate attempt produce enough performance to allow you to keep up with me.
So for me at least, back to square 1. My bike's cool because Soichiro san designed it that way. Your bike's hot for exactly the same reason. But again... that's just one untutored opinion innit
Eliminate the impossible. Whatever remains, however improbable, must be the part you forgot to service.