Joseph Smith's importance

I understand that Joseph Smith is extremely important in the LDS Church, but to what degree?

Is it possible to be a member of the LDS Church, accept the basic tenets of Christianity, but at the same time reject the revelations made to Joseph Smith? For example, to agree that he was an important theologian and organizer, but reject that he was a prophet or had visions?

I know that some members stay in the Church mostly because of the community and its values, but I would like to understand how central Joseph Smith really is.

Also, do you know if, in LDS congregations around the world, Joseph Smith is given the same level of importance?

Thank you in advance!