I am an agent as is sdrealtor. He is right about procurring cause however it does not sound as if they would come after you in this particular case. (that is just my opinion) Similar to a listing agreement (signed between a seller and an agent) when a seller is listing a home to sell, there is a buyer broker representation agreement that does obligate a buyer to be represented by a broker. If you have not signed such a document, then it is unlikely that representation would be challenged, IMO.
On the personal side I am renting right now. The 1 year lease goes by VERY quickly. Consider that the risk of the market appreciating 1 year from now verses depreciating 1 year from now is pretty low. (At least that is my hope) Also if you have downpayment money stick it in a cd for a year and grab 5% on it. So if I were you I would not fret much about waiting.
If you do have an agent who has done work for you then “the ethical” thing to do is to work with that agent. However if you have clicked on a schedule an appt or gone to open houses and talked to agents who were holding the open house, you are definitely not obligated, especially if you did not sign any agreement for representation. As a courtesy though you may want to tell them that you are already working with someone, (and that you very much appreciate thier time to show) if you do not intend to work with them.
I have spent many weekends with clients only to get scorched by mortgage brokers or other agents. It is part of the business. While we are considered fairly useless by most on this forum, many of us are helpful and can very much help people save time, money and find/sell thier home.
