Sorry to hear about the run around but that is probably the nature of the publishing business. There are simply so many people out there with differing opinions and it is often hard for new writers to really determine what works and what doesn't work. I will say, by the looks of your email, you are heading in the right direction.
Now, first of all, there really isn't a right or wrong approach to finding an agent, or for that matter, pretty much everything out there in publishing. The approach you take will depend on you, your needs and certainly your manuscript or genre you write in. A writer friend of mine posted this on her Facebook page and frankly, Nora Roberts is right on the money with this answer. With that said, while there are no right or wrong answers, there are certainly wrong approaches for your individual situation. In other words, you might be looking in the wrong place for the style of writing you do and so forth.
When it comes to finding an agent, I always recommend beginning the search with yourself. You have to determine the following things before you proceed:
- Where do I want to be published?
- In what format do I want to be published?
- What publishers represent my type of writing?
- What are my personal needs as a writer? This could include editing, marketing, general knowledge and so forth.
Once you have that list in mind, now comes the search for an agent. Of course, you might have determined at this point that an agent isn't something that you need so therefore you would stop her. But, let's assume you do need the agent.
There are certainly several approaches to take. Based on your comment, you are taking one of those approaches.
Web Databases - Query Tracker is certainly one of those sources you can start with. There are obviously a lot of other databases and lists you can work with. If you are part of a professional writing organization, there is probably a list they have composed available to you. Start literally at the top of the list and start looking at everyone. Review what they represent and learn everything you can about that person. This could include whether or not they are accepting submissions, comments and feedback about the person and so forth.
Do understand that these databases have their limits. I personally recommend databases that come from the professional organizations. These groups tend to have standards for being listed and will often weed out those people, as you noted, who are "questionable." When it comes to sites such as Querytracker, you may find that only people who didn't get what they wanted post information and therefore it tends to give across a bit of a negative spin on potentially a good agent.
Asking People - The more you talk to people, the more you will learn not only about agents but also about people in the business. Again, remember that this information may be a bit biased so keep you mind open and use your brain.
Books - There are a ton of books and resources out there that list agents and editors. The approach here is the same as what you would take with the databases. Start with your list, start at the top of their list and work your way through, finding all of the people who are an exact match (at least 90%) of the way there. Once you have that list, start your research on that person just like you do with the databases.
Conferences - Writing conferences will always have agents at them. Attend the conference. Ask questions. Attend the agent panels where they get a chance to talk and chat about what they want and don't want. There is nothing better than hearing it right from the agent!
Blogs - There are still a few of us out there that blog. This is a great place to really learn about the personality of the potential agents. Now, a lot of agents tend to use Twitter and other social media sites. Unfortunately, this might not give you as much information as you want or need.
I think the key to all of this is research. There is no single easy approach to finding an agent. This business takes time to be successful. Don't rush this and really spend the time getting to know who is out there and your own personal needs.
I would also add that it sounds like you are just beginning the writing journey! Good for you. I am betting that you might not be in the position yet to look for an agent so use this time to create that "damn good story" and learn about the business before you jump. There will be many who tell you that you can't do it. There will also be many who want to tell you the "best" way to do things. Listen but don't jump immediately. Take that information and learn first!