No experienced agent drives people around without a qualifying interview first. Also, a good agent will have you begin the loan process immediately. We're not talking about getting pre-qualified, we're talking about getting approved for a loan. This will put you in the strongest possible negotiating position next to buying with all your own cash. In today's market, having your loan in place before making an offer is mandatory.
Most homes have multiple offers.
Sellers are not even looking at offers for which the buyer does not have the loan in place. The buyer is responsible for applying for his loan. When the buyer's loan is approved and documents are ready for signature, the lender delivers the documents to the escrow holder, usually a week before the closing date. The buyer signs all loan documents ahead of the closing date, and the seller signs the deed a few days before closing. One or two days before closing the buyer delivers the remainder of the down payment to the escrow holder.