From my research public transport in KC is abominable. Other than Boulevard, are there any other breweries worth making a trip to within reasonable distance (30 mi) as I'll be having a car. And for the weekend nights, is there a good area with bars that have good local beer selection close by that I could walk between?
Check out craftbeerkc.com or the search function yelds this: http://www.beeradvocate.com/community/search/29950218/?q=kansas+city&o=date&c[node]=11
Cinder Block and KC Bier Company are worth the drive. So for bar areas...Westport has Beer Kitchen, The Foundry and McCoys (brewpub). Further south is Bier Station. Way further south are 3 different Barley's and Martin City Brewing. I know I skipped stuff that others will mention, but I was trying to be concise.
Big Rip Brewing is really close to Cinder Block. Sadly, both places don't show up when you click on Kansas City breweries, because they are in North Kansas City.
For walkability, I'd either stay Downtown or Westport. For downtown, you can walk to the Flying Saucer, The Belfry, and Anton's. In Westport, you can walk to Bridger's and the BeerKC establishments (McCoy's, The Foundry', Beer Kitchen). I'd probably give the slight edge to Downtown, because there are way more hotels available. I can only think of a couple of hotels in Westport (the Q Hotel and 816 Hotel) while there are tons downtown.
ig88b is right on, but I'm typing from Westport right now. The Q is closed, under renovations, but the Embassy Suites (hotel) between Westport and the Plaza is within walking distance. McCoy's (ask if Keith the brewer is in, great guy) and Beer Kitchen have great beers (the nod goes to BeerKitchen for it's food), and the Foundry has to be experienced for any beer lover. Wesport is just a cooler, vibey-er area, vs. Power and Light, or Plaza, etc. My .02....
For the love of god, don't forget to get some BBQ while you're down there! So many gems in that city. I've been to Gate's and had their burnt ends, and it was life changing. And I've heard there are better places than that.