In your last post you said: "Man, I gave you a few links on the first page of this thread, they were wikipedia articles about Bosnian ban Kulin, and about Bosančica." so i answered link by link, i did not see a link for Bosančica or Stećci. But ok, lets answer those 2 as well.
What you call "unique monuments of Bosnian people" i call nothing but a custom that appeared during times of Bogumils: "Although its origins are within the Bosnian Church, all evidence points to the fact that Stećci were erected in due time by adherents of the Orthodox, Catholic and Islamic faith alike." (from their wiki article) which pretty much tells us that this is a custom that started during the Bosnian (heretic) Church, and was simply carried over later by next generations. They werent built by all people who lived there (or else youd have hundreds of thousands of them) but by smaller portion, and for that alone you cant call them a thing that separates all Bosnian people as one culture. Further more, customs alone are not enough to define cultures. As someone else mentioned, Dalmatia today, as it was a thousand years ago, is completely different in customs to northern Croatia, and so is Serbia in every single way (its probably even more drastic as the country's geography drastically changes).
Im not a linguist, so if someone knows better please correct me, but before this guy Vuk Stefanović Karadžić (19th century) no Ex Yu country had a universal and standardized system of writing. This is relevant to 10th+ century in terms that the only people literate at that time in our lands were the monks who lived in monasteries and copied over again and again various church scripts and books. We did have Cyrillic script but it was not a standardized alphabet, as in the same used by all, but it was more like a monastery-to-monastery free interpretation of that, so over time different version of it appeared in different areas, the way i see it, the language that it symbolized was more important than the style of its characters. This is something that you can use as argument for culture: http://en.wikipedia.org/wiki/Serbian_Cyrillic_language because we know a.) who developed it and b.) when it was developed. Furthermore when you go on to read where Bosančica was prominently used, this is the number one listed thing: "Passages from the Bible in documents of Bosnian Church adherents, 13th and 15th century.", which again makes perfect sense. If the heretic monks used an alphabet, it certainly wouldnt be the same as one used in Serbian Orthodox monasteries, since these Bogumil writings would never be allowed nowhere near. Instead they had to be written/rewritten by others, so thats how this different tradition appeared. Another interesting detail about this issue, when you scroll down on its wiki article, to the Controversies and polemic, the very last point states: "Bosniak (Bosnian Muslim) scholars have always considered that the Bosnian Cyrillic is neither Croat nor Serb, but ethnically Bosnian and, subsequently, Bosniak, as the supposed ethnic successors of medieval Bosnia and the native Bosnian Church." which kind of illustrates what i was trying to say without saying it all along.
