If you want representation then sign the papers.

Is the buyer/broker agreement for any property or is it specific to the subject property?

No, an exclusive buyer's agent agreement is not required legally. Some agents however require it. Your agent should have discussed this with you prior to sending it.

Typically, if a realtor has showed you a property they want you to purchase the property through them as they have spend time and resources to which they have not received any compensation. 

It sounds like the realtor wants you to sign a 3 month exclusive buyer/broker agreement on the house you made an offer. You will have to read the agreement and see if the realtor has identified the property to which they want to sign an exclusive agreement with or is it covering all properties the realtor has showed you. 

It is for our team, why waste time on a buyer that is not serious enough to be our client?

There is no contract that you are required to sign.  You may need legal advice before signing anything that you don't understand or are being coerced into signing.

Ask your broker.  We don't know the answer to a question that might be state or county related.

Robert Gillen In my State BBA's are mandatory.

What is "required" changes from state to state, and even from brokerage to brokerage within each state.  If you have questions, I would sincerely encourage you to speak with your broker first, vs answers from others online.

That is a state by state issue....

No...it is not...the agent should have discussed with you the pros of being represented and what it means if you are or are not before including it...ask first....negotiation on your behalf rather than the Sellers' can be a big plus.

This question lacks some details but you are not obligated to commit to any contract unless you choose to do so.