I received an insurance quote that I was hoping to get some feedback on (first time shopping for rental property insurance).I figure there are unnecessary items on here increasing the price, but I could be wrong.

I'm estimating property taxes and insurance at about $450 monthly. 

We had checked references and verified he was licensed, bonded and insured the first time we worked with him.

I'm getting bids from GC's (example: $6400, $6500) and found another guy off of facebook for $5400 (supposedly insured).

You can fix that by replacing the current one or by enforcing your policies and procedures, if you have them.What does your lease say about late rent?

There are some inconsistencies in the law, and policy currently but that will get worked out.

I am interested in exploring other insurance company options for my 4unit building in Long Beach.

Talked to the mortgage company and they said 2 things happened. 1, they added some extra insurance to my account.

Can anyone recommend a good insurance agent for a flip in the Chicago area?

You'll get more accurate advice and answers, and they will probably be more willing to work with you and guide you in the right direction if they have documentation to look at (tax returns, W2s, amounts you paid for each property, taxes, insurance costs, estimated rents and completed values, etc).