You are the king! I could line up a sizable collection of expendable ships but nothing like that. Nine hours would definitely not have been a 25 cent adventure for me.
Your method of staying alive sounds a lot like mine. Make good use of salvos, follow the rocks as they near the edge of the screen while blasting them and just before they reach the edge pivot to face the emerging edge and begin blasting so that many never made the jump. Also, when you get down to the last couple of rocks just put yourself behind them moving in the same direction as you destroy them and accelerate as the last one falls. Then use a slow fan salvo as you rotate and glide to try to score the spaceship but get ready for a quick pivot if you're out of position.
I also am not near as fast on the uptake but that doesn't keep me from getting caught up in it. I have a Wii, an XBox360, numerous pc games and a Steam account, and that Atari emulator. Asteroids is always a favorite. I'll never forget the awesome feeling I had when I sat down to an Apple IIc in my first college computer science programming class and started following the simple instructions we had been given to draw an object and move it around on the screen in Logo or Turtle or something like that.
I was getting a glimpse of the process behind making a game like Asteroids and I went from a person who had no interest in anything having to do with computers to someone who has now spent his life in an industry that depends on high performance computing.