Hi OP, I am from the Balkans and first of all let me say it is really commendable that you want to read and learn about the region and especially this difficult part of our history. I tend to avoid war-related literature but would just recommend checking the background of each author and maybe book reviews, so you understand the particular perspective that they are coming from. Even nearly 30 years later, one thing I can guarantee is that there is no such thing as an objective account, which is understandable, but it's important to know where an author is coming from. What was their experience of the region, of the war, etc. and how does this colour their storyline.
One "narrative" I would be particularly cautious of is the "primordial hatreds" or "ancient ethnic hatreds" one as it has been shown that ethnic tensions were in many cases stirred up by war profiteers and nationalists, not an inherent inability of different ethnic groups to get along.
The one I would avoid is Misha Glenny.
Second, I would just add a quick warning that not everyone will want to talk about the war. I'm sure you didn't plan on accosting random waiters with questions anyway, lol, and there are lots of people who are happy to talk about Yugoslavia and the war. But some are understandably still sensitive so would just keep this in mind. Can't remember where it's from but I read a quote saying something like, people either refuse to talk about the war, or it's all they can talk about.
With this in mind, some people are also sensitive about the region only being seen through the lens of the wars. I'm not at all suggesting this is you and 100% get where you're coming from, but again just something to keep in mind. Off the top of my head, amazing authors from the region translated into English are Ivo Andrić who was a Nobel Prize winner, born in Austria-Hungary and active in Yugoslavia (The Bridge on the Drina), Slavenka Drakulić who writes touchingly and hilariously about Yugoslavia although she arguably exaggerates some of the downsides (How We Survived Communism and Even Laughed), and Aleksandar Hemon, a contemporary Bosnian author who bridges the Balkan-Western experience really well (try The Lazarus Project). Happy to add more but it looks like you have quite a few recommendations already!
Third, if you're interested in the legacy of the Balkan wars and you have some flexibility in your trip, I would highly, highly recommend spending some time in Bosnia - Mostar, Srebrenica, and Sarajevo. They are difficult but beautiful, culturally rich, and historically important places to visit; for someone who wants to know more about the Yugoslav Wars, Bosnia is indispensable given the horrific genocides that went on there and as many of the tensions were worst there given its large Muslim population and that it was a tri-ethnic, tri-religious state.
Safe travels and I hope you find some good reads ❤️