It's hard to say exactly. The progress of the light novel's arcs might not align perfectly with any specific point in the story. You'd need to check the latest releases for accurate information.
Re:Zero's light novel has gone through several arcs. The arc it's in can change depending on new installments. It's best to follow the author's updates or check reliable sources for the most current arc information.
Yes, indeed. The Re:Zero manga exists and presents the story in a graphical format. It might have some differences from the original source, but it still captures the essence and excitement of the series.
I'm not entirely sure specifically what 're zero light novel to arc' refers to. It could potentially be about a particular arc within the Re:Zero light novel series. Maybe it's about a specific story development, character arc, or a key plotline within that part of the novels.