there's will be sharing limit everytime but i dont know how many the limit is.
when you got notice from facebook regarding multiple post in the same time, you should stop a while.
i have experienced they(facebook) warn me for not making too many more post.
so at that time i try to make some delay 5 post for every 20min - 30min and everything is fine till now.
i can do task for all my bountyjob and my facebook is save.
for this forum, i try to minimize my bounty report everyweek in this forum and also contribute by trying to make some quality post in return for my bounty income.