Reverend, pastor, clergy, minister, preacher...they are all acceptable. It is more of an issue of preference.
Call her Mrs Reverend
The address should read: Reverends (or Pastors) John and Jane Doe.
Methodists pray in Churches like other Protestant Christian Denominations.
An envelope should be addressed to "The Reverends John and Mary Doe" An acceptable alternate would be: The Reverends, Mr & Mrs John Doe"
Methodists call their clergymen ministers, instead of priests.
If the church is a congregation, they would be called congregants. If it is a parish, they are parishioners.
You could address it to Reverend and Reverend Smith. The alternative would be the Reverends Smith.
Yes
Brahmins (Brahmin Reverends) guided by Maha Brahma(Unseen God).
A group of Pastors
While there are diffrences in beliefs, Methodists do not hate Catholics.
Association of Independent Methodists was created in 1965.