I really enjoy this series.
I can't help but wonder if the reason Tanjirou never really had a clear romantic interest is because he won't be around for it to come to fruition. Not that a story really needs a clear one, though.
I really don't see Nezuko dying in the end, since the whole journey has revolved around getting revenge and ending Muzan to save her. That said, it doesn't mean that I'm not expecting some bad stuff to happen as a red herring. When it comes to Tanjirou on the other hand, I'm not so sure. Feels like his survival could go either way.