My friend has been a 5 for months and I can stay with him tied up. I never play 9 ball but when I do I can run 5-6 balls on average. As for 8 ball I usally average a 5 ball run. Sometimes I'll run off 6 or 7 and screw up shape on the 8. So I try not to clear all my balls unless I know I can pull shape on the 8 ball. As far as people marking safeties I doubt my team captain knocking back miller had a clue as to when I shot safe.
You sound as if you're a solid SL5 to me.
As far as the scoring goes, a large portion of APA players that keep score thinks that a safe is a small metal box under the bed for hiding their life savings in. One night after the play was over, we had marked 27 defensive shots on our score sheet....they had marked 2. I have also seen where their scorekeepers mark several innings per game more than I had marked on my score sheet, and an unwillingness to change their marks. It is what it is.
As far as people telling you to just show up, play your best, and have fun with it....this is sound advice. No sense of getting worked up over a handicapped league that determines your skill level depending on how well the scorekeeper does their job.
I am a SL7 in 9-ball and a SL6 in 8-ball. I've just come back to league play after a 3-year hiatus. At nearly 64 years of age I can no longer play at the level I was playing at when I left, so I just make it my personal challenge to outrun the handicap. But as far as the winning and losing go, I couldn't give a rat's ass. If I wanna go to Vegas, then I'll buy a plane ticket and go.
Good luck and enjoy!
Maniac