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.
The 're zero rem love novel' is significant as it expands on the Re:Zero world. Rem's love in the novel is a key element that drives her actions. It shows how she develops feelings for Subaru, and this relationship is a major part of the overall narrative. The novel can explore her emotions and internal struggles in a more detailed way compared to other mediums.
It depends. Some elements from the comics are incorporated into the MCU movies, but not everything is considered canon. The MCU has its own established continuity and storylines that may deviate from the comics in certain ways.
In many cases, it's up to the creators and the established lore. Usually, if it's explicitly stated within the franchise's framework or ties in seamlessly with the main storyline, it can be considered canon. But there are always exceptions and nuances.
The light novel's ending is crucial as it ties up many plot threads. It gives a sense of closure to the characters' arcs. For example, Subaru's growth throughout the story reaches a culmination in the ending. It also reveals the final fates of other important characters like Emilia, showing how their relationships have developed and changed over the course of the series.