Need Help with Reviewing Offer Agreement with a Real Estate Agent

[Masashi Borges-Silva]

I need your help for me to understand my first "offer and agent agreement".

The background: I am the buyer, and this agreement is between my real estate agent and me (client).  I am buying a house from a seller with the seller's financing.  One of the options that the seller is demanding is for them to stay in the property for two years for free in exchange for 0% interest rate, and they plan to move within after the two years. 

I am compiling an offer for the house, and the agent is asking me to sign a document that has language that I am not fully understanding.

In my understanding, the agent's commission is paid by the seller, but in "Client's Obligations" it seems I am responsible for 3% of the purchase price of the property or 50% of the aggregate rental of the lease and all options as exercised.  I am not sure how "50% of the aggregate rental of the lease" would mean for me financially.  I am assuming this is the language used for a rental property, so 3% applies for this instance, but I thought the seller pays for the commission.  Are commissions and compensation are treated separately that the agent receives 5% total from the seller and the buyer?

Below mentions of "the Seller shall pay the broker's commission of 2% to my agent."

Then also, below mention of "50% of the aggregate rental of the lease and all options as exercised"