It's broke in, let er rip!
I'm thinking around 8k or so for V-twins. I know I shift when I hear the rev limiter on my Shadow.
I don't rev the piss out of mine but staying in the rev range where you have good throttle response is the place to be to get out of trouble quickly if needed. It's a Honda, you aren't going to hurt it.
When it starts blowing oil out on your right leg, you've been a little hard on it. It will blow out the relief valve by the air cleaner if the pressure is too high. This only happened once on one of my Shadows while trying a top speed run in 5th gear. I guess that was a little too hard on it. I checked the oil and it was fine and that was a few thousand miles ago and the bike is fine.
It also happened once on my buddies Vulcan 2000 when he encouraged me to let it rip to feel the power but he had grossly over filled the oil the day before, his fault. It blew out a lot and the dipstick was still wet all the way to the top. I should have rode it longer.