No it is not over pitching. You don't need to aerate you wort because there is already enough live yeast to get the job done. I have waited as long as a week, As long as the Air Lock was on I would say the longest would be about a month, I would not try that tho. But if you needed to keep it longer, I would suggest cooling it off in your fridge. My SWMBO may not like that to much tho...
Glad to hear your Belgian is ok. I would think that after 10 days it would be close to being finished. I have good success with 1762, so hopefully you will also.
Cheers
Preston