@v4 I think there´s already a plugin that lets you do that, show the N last posts from a category in the home page. Since you only have one category, i think that meets your requirement. Check the plugins category in this forum, i think you'll find it there.
But that's what pagination is for. And if after 5000 posts the subject of the original topic has not been resolved, then it will never be.
I have a tutorial on my blog with more than 550 comments. If I had a good forum platform with a good search feature, most of the comments would not have been asked.