Most of my clients, while we place an offer on a home, and try to contact the listing agent on a regular basis for updates and any other angle we can to get in 'partnership' so that the lender is reviewing OUR offer as the preferred buyer, still continue to search for additional homes and stay on top of the market for additional opportunities. We (my buyer and I) can't wait for one particular home as there's no guarantees.
If you are already working with a second realtor for the other opportunities, then you could ask them to call the listing agent on this particular home and see if they get the same story as you are receiving. In most case, you could be reassured that the situation is what it is. If you find that your first realtor is not representing you correctly then you could contact their broker or work with them to improve that service.
I guess that much of the frustration you are feeling is actually frustration with the market, not in something that your realtor is not doing for this transaction...if you selected an agent experienced with this current market.
Good luck to you! I know it's not much of a consolation, but you're not alone in feeling frustration in this market.
I personally would not want to take over another agents escrow without their permission. ( and the probable payment of a referral fee)
By the way, to clarify. The agent that represents the buyer has no control over the MLS status, unless they are a dual agent and also represent the seller.