Here are my thoughts. I wouldn't call myself an old pro, but I have successfully navigated all of your questions at least once or twice (other than #1)
1. I would send beers you are considering to one of the solid competitions in the area, that is known for good judging. Check the WAHA website for Washington competitions (we have a lot).
2. Conference tickets go on sale in February. The exact date is announced a few months in advance. I would recommend taking the day off from work if you can, the tickets usually sell out within 24 hours. I think this year was within 8.
3. My wife loves to drink beer, but is not overly interested in what is behind making beer. When we went last year, I got a full ticket, and she got a social. That is what we are planning on doing again this year. The social package gives you access to the "drinking" events, such as the hospitality suite, Club Night, Pro night. The only thing you don't get access to is the lectures. My wife plans on exploring the city during the day (likely with a couple other spouses). I also recommend getting a ticket to the banquet (even if you didn't enter a beer). Chef Sean Paxton makes some amazing food with beer, and it is always some great conversation and camaraderie over beer. I think overall (1 full, 1 social, 2 banquet) it was about $400 for the event. I think all tolled (Cross-country flight and 8 nights in the hotel across the street) will be about $3000, including food.
4. Talk about the events. I guarantee if your wife drinks beer, she will want to go to the social events. Pro night is great because a lot of the breweries bring some really interesting beer, and it is all free. Club night will have some of the most adventurous beer you well ever see (Bacon Ancho Porter, Apple-pie Scotch, Wee Shroomy), and everyone is extremely friendly. If you just convince her to go the first time, you won't have a problem getting her to come back. Last year when my wife showed up at pro night, the first thing she said was "Ok, We're going to Philly next year."
That's my 2 cents.