This question relates back to your previous question about commissions . . . and I'm glad you posted this since it does clarify that you're the buyer.
We can't give you legal advice. For that, you need a lawyer. However . . . .
As I and some others noted in our answers to your previous question, a buyer's agent can ask for a commission if the seller isn't paying one, or the amount to be paid is insufficient. And that's what those sentences provide: If not enough is coming from the listing agent, then you'd be responsible for the remainder.
Such wording is fairly common. Remember, though, that it's all negotiable. It appears, for instance, that your agent is looking for a split on a 7% commission. I don't know what's typical for your area, but regardless of what's typical, you can try to negotiate that down.
Your agent is also setting a minimum on the commission. And that, too, is negotiable.
Remember that--as a practical matter--if you're buying a house already listed and it costs more than about $60,000, you're not likely to pay much or anything. Just if it's a cheap house with a discount broker (Paragraph A) or a FSBO (Paragraph B) are you facing some exposure.
From the agent's standpoint, the agent is just trying to make sure he/she gets paid something for the work he/she is doing on your behalf. But if it makes you uncomfortable, negotiate on those points. Or make sure that before you put in an offer on a property, that the commission will cover those amounts. Or be willing to pay.
Again, that's not legal advice.
Hope that helps.