Okay, people are being a little silly here, and I just wanted explain the meaning behind some of the warnings you've got, just so you don't think they are being dismissive of your post etc.
Caps lock: Typing with the caps lock on makes it come across like you are shouting. Agents obviously aren't afraid of capital letters, but All Caps can make an agent cringe because it seems like you are yelling at them. Now I don't think you would send anything to them all caps, especially because your post isn't in all caps. I think what you did was create a title of a thread in all caps because you thought it looked more like a proper title. But you don't have to do that here, and it will come across as shouting even though that is so not your intention. Ditto if you made the subject line of a query letter to an agent in all caps. It is best not to do it. The exception is when you are putting the title of your book in the query letter itself.
The second point from herdon is just clarifying terms for you. You don't blog on a forum, you post on one. Sometimes, like you did here, you start what is called a thread.
As to your actual question, you are free to post a doubt and any agent worth his/her salt shouldn't take offense, so long as you post it in a reasonable fashion. Something like, "I hear Ms. Smith is a bitch" is not so fantastic. But something like, "I hear Ms. Smith isn't good at communicating with her clients and has broken contracts" is better.
But make sure before you post anything that you do a search. Tons of agencies have been posted about here on AW, and you might find the answer to your question without even having to start a thread.
Good luck and welcome to AW!