wouldn't a diehard sportbike rider be someone who drives on the street during the day and then races on the weekend on a track with a race prepped bike? if so there are plenty of them here. not me yet though, I understand where your coming from about the speeding when I was younger like 15-17 I did much of it, then I hit 19 and realized that street racing is more for kids and not worth the risk.
about the harleys, we defend them because it not worth starting flame wars. the more of us there are on 2 wheels the better our stats look period, no arguing over style. its like caddys and corvettes, which would you want, but you like both right?
about your bike, I never believed miles make or break a vehicle. but if your going to try and sell it on a site where you brag about how hard you run it then of caorse they are ging to give you like $800 for it. put in on cycle trader with a picture and you'll get 3500-4500 for it, good luck