Indeed, the text is tricky, even native speakers have to read carefully to understand it.
I don't think so. The meaning of the text is absolutely transparent, there are only a couple of outdated word uses. For example, a modern Russian speaker would say "избежал" instead of "избегнул", "под самой кровлей" instead of "под самою кровлей". Everything else is completely normal for modern Russian.
On the other hand, the language style of this book is heavy but it's quite appropriate for a story of a poor student obsessed with an idea of strong individualism going to kill an old woman with an axe.