Hi there, I agree that the travel agent is the most important person in the process. if they say they do a lot of weddings, well that's a good start but it still is not a guarantee that everything will go as planned as most travel agents look after travel & flights not planning the actual wedding.
It basically comes down to how hands on you want to be in the planning of your destination wedding. If you love planning and have lots of time to figure out everything, then the travel agent will usually give you the details to contact the resort wedding department or head office wedding department and it's up to you to figure out all the details of the wedding, while they look after the travel & accommodation details. This is a lot of work and often this is what frustrates most brides.
If you would like some help but still want to be involved then there's some travel agents out there who have also decided to specialize in weddings - they are usually called Destination Wedding Specialists. They will usually contact the resort on your behalf and book the details of the wedding as well as the travel & accommodation, sometimes for a fee, sometimes it's included in the commissions they receive. They will then hand the reigns over to you and you get to figure it all out when you get to the resort.
Or there's the highest level of personal care and that's a destination wedding planner who will liaise with the travel agent, the resort and your guests as well as travel to the destination with you and take care of everything for you when you arrive, this is for you if you hate planning, are unorganized and just want to enjoy everything but comes at a higher price.
So start with what type of service you are looking for then you can work out who is the best fit for you.
I would recommend a travel agent who specializes in weddings and also does specialize in your country of choice but this might be hard to find if you want to get married in Bali or Thailand as not a lot of US travel agents specialize in this region. So do not be afraid of using a travel agent in another region/country that has expertise in this area.
As for an interview, this is not a standard practice - as they are not employees, they are consultants. So a "meeting" would take place where you are both evaluating each other rather than you interviewing them, as not all travel agents want to work with all brides, just as all brides don't want to work with all travel agents. It's a very personal journey that you are both entering so it's good to know you can work together well, and don't rub each other the wrong way. This is a good time to ask lots of unanswered questions and answer lots of questions as well, so you can both get a feel if you want to work together.
Lastly the quote will be very specific. You will not be able to get pricing/incentives/perks without specific dates, group number estimates, flight hubs or where the majority of your guests and you are flying from, and the specific resorts you are considering. After you know these details then they can see what offers are available to pass onto you as these change from week to week. An example of a "perk" would be if your group books 10 rooms then your room is free.
Hope this helps and let me know if I can answer any more questions.