I have a couple things to add to this discussion for now...
Wine
I had been on the search for a great wine store since I moved to KC from Ann Arbor, MI 3 years ago. Prior to a recent discovery I was relying entirely on Consentino's in Brookside, Costco and Lukas Liquor. My main problem with all of these places is that they focused heavily on California wines. Lukas Liquor probably had the best overall selection, but it's a pain for me to drive way out there just for wine. Consentino's has great prices and selection for being a grocery store. Costco, of course, has great prices and a good, yet limited, selection. I have been through several other wine/liquor stores in the area, but those three served me well for a while. I absolutely hate Berbiglia for anything (wine, beer or liquor).
My recent discovery was a shop just called Wine. It's located right in Brookside on 62rd St on the same side of the road and just a little bit down from Charlie Hooper's. I was shocked after a thorough examination of their selection. They had the expected high quality cabernet selection, but also excellent selections from regions other than California. I wasn't exactly on the hunt for a bottle, but I ended up walking out of there with a Jermann Pinot Bianco, a great Spanish Rioja Crianza and a bottle of Unibroue's 17th anniversary beer (dark Belgian style). I was also happy to see a nice representation of Oregon Pinot Noir and Washington Chardonnay, which is something I always look for. I also spotted a few bottles of Roederer Crystal Champagne, which brought to mind a lunch at l'Ambroisie in Paris (decadent, sentimental). In addition to the selection, I think their prices are right on and they're locally owned (by local I mean the owner lives in Brookside). They also keep a level 2 sommelier on staff if you have any questions. Lastly, they also hold wine tastings every Friday from 4-7 PM and due to the proximity to my house, I'll probably be there every Friday (including this one) with my wife and friends. Yes, I am infatuated with this place.
Seafood/fish
What is a good place for seafood/fish? Costco has some cheap stuff, but the quality seems questionable with certain things (I usually just buy trout there). McGonigle's selection seems to be very good and I have gotten fresh hamachi from there before, but at a price. McGonigles will also order pretty much anything too. Whole Foods seems to have a decent selection that looks high quality. Attempting to find seafood/fish in the middle of America can, of course, be challenging, but I'm trying to identify a good source for it.

For wine, may I recommend
Cellar Rat in the Crossroads - knowledgable, friendly staff, great variety and frequent tastings/events. They also make their own fresh mozzarella and stock various
delices. For a more warehouse approach,
Riverside Red X has a vast selection of wine, beer, liquor (as well as a grocery, tobacconist, dollar store, tools - and 'historic' items - must be seen to be believed).
Seafood is a challenge in these parts. It sounds like you've found most of the spots. McG's will order just about anything for you (I called yesterday and am picking up some barramundi in a couple of hours). I have had mixed luck at Dean & DeLuca and needless to say it's not inexpensive. There is a high-volume Hen House on the NE corner of 119th & Roe that seems to have better seafood than many of the other locations (they also have kosher certification and offer a variety of kosher foods). Depending on what you're looking for, the Asian markets in the City Market area might be a more budget-friendly option. The large market to the northeast in particular has a lot of fresh fish, some in tanks, and you can predictably find head-on shrimp and the like as well as some more exotic species.
I still miss the VC (Village Corner), Merchant of Vino, The Party Shop on Packard, Sparrow Meats and especially Monahan's - so I feel your pain!