I'll first start by saying that the KeyBank Center has seen better days and lags far behind the types of amenities that have become commonplace in arenas that are newer, better maintained, and/or forward thinking enough to seek opportunities to improve the fan experience.
To answer your first question, there are no sections with booze/food included in the price of the ticket at KeyBank Center. The Club Level (aka 200 level) does offer in seat service for bar and food items.As for the club level being worth it, that's very much a matter of perspective. For my money, the club level offers, IMHO, the best views of the game in the building. The seats are more comfortable and more spacious, there are less fans to deal with for bathrooms as well as food and bar service.
There is a large bar area that has some first come, first served tables available. There's also a pretty large area with many tables - again first come, first served - that is closer to the arena bowl itself. So, you can head up there a little early, grab something to eat and eat it at a table before heading to your seats. There are also some bar style seating areas that allow you to sit next to each other on bar stools, eat/drink and watch the game. But you have to be early to secure those.
There are also ticketed tables that are yours for the game - but I don't know how they are designated on a seating chart. You'd have to call the ticket office to inquire about those, but my understanding is that they are tough to come by.
Everything is relative when it comes to value. I'll stop short of calling KeyBank Center a dump, but it can be dumpy in some areas and ways. I can say that I've always enjoyed the games I've gone to when I sit in the Club Level. It's not state of the art but it's also definitely not dumpy and, again IMHO, it's the best that KeyBank Center has to offer for gameday experience.
If I'm trying to make my out of town visit to a Sabres game as special as I can, I'd go for club level seats, get there early - grab some food and a table, watch the warmups, hang out at the bar and the head to my seats - from which I can order additional snacks or beverages