I haven't tried this board so take this with a grain of salt. I have owned a few Longboard shapes and I really like them. They catch waves really easily and because of the outline they are quite stable. 28 wide might be less so but probably not too bad. The boards I've had like to be surfed from the back but they aren't too bad from the middle. I'm not into nose riding either but it's still fun to get up there on a fat wave.

Yes, all else being equal 6'' length is quite noticeable. But the longer you go the more drawn out the turn especially with small waves. Not knowing anything about you or where you surf 9' longboard might be a nice size at 70kg.