I've also heard that using a realtor, particularly on larger deals, would only slow down the negotiating process and introduce another layer of communication that could cause misunderstandings and confusion.I am a newbie and wanted to get feedback from the BP community on whether I should continue to use her or start negotiating deals myself?

That requires to entities or departments actually communicating. :)

Any references should have good communication skills and do quality work.

Answers to any or all of the 3 questions above is greatly appreciated.Thanks so much! 

My property manager told me communication with them is also very hard as well.

Then don't forget the issues working in an occupied unit (noise, communication, tripping, etc).....

I hope to connect and work with some or all of you here at some point!

Then within a prescribed time if the conditions of the unit were worse or had other problems upon discovery you could then take some or all of the sellers holdback funds in escrow.Remember once a seller closes and gets all the money they vanish most of the time....... : )Doing hold backs and other procedures helps keep them honest and not play games.

It's always a good rule to maintain open communication with team members to avoid wrongful assumptions, plus it provides you feedback (what the realtor can do/not do to help) to see if the person is actually worthy of being on your team.The realtor should also be able to provide you with searches specifically for owner finance properties. 

Generally speaking, if an agent shows you more than one property, you should clearly communicate to the agent whether or not you are calling other agents.