As someone suggested, watch C2 training video if you can. Also makes a big difference on how big you are. Bigger guys naturally tend to have a slower rhythm, than a smaller guy. And what kind of workout you're doing will also dictate the pace.
When I'm trying for a 500M personal best, I'm running a mid 30's stroke rate. An aggressive workout or a strong 2000 meter pace and I'm in the high 20's or low 30's. If I'm doing a long slow workout, it's mid 20's for me, but everyone is different.
8:46 for 2000M is decent, but not setting the world on fire. Again it depends upon age, weight, size, etc. Sub 7 minute and you've got something to brag about.
I have rowed over 500,000M in the last three weeks for the challenge and yes I live on the rower.
But I'm rowing at a very casual pace for me.