- How do people know that they're part of the Faithful and Discreet Slave Class?
The usually cited text is Romans 8:16: "The spirit itself bears witness with our spirit that we are God's children" (NWT). They just KNOW, because the Holy Spirit causes them to know. Unfortunately for the JW position, there is nothing in the context of that passage (or anywhere in Romans) that states or implies that such 'bearing witness' by the Spirit is characteristic of only a limited number of Christians, to the exclusion of other Christians. The two "classes" that Paul speaks about in Romans are those who live by the flesh (who are not of God and face condemnation) and those who live by the Spirit. No room in this chapter for earthly and heavenly classes.
- How is seniority established?
I don't know that seniority is really relevant among the JW anointed.
- How are they so certified by JW leaership?
They aren't. They simply declare themselves to be of the anointed class, generally by partaking of the elements of Communion at the Memorial. there are also a few internal forms (like pioneer and Bethel applications) where they may have to check off a box indicating which class they belong to.
- Don't many people consider this sort of thing to be self appointment?
Yes, and I'm one of them.
- Is one generally considered to be part of an elevated status to be in that class?
Yes and no. Many individuals among the "other sheep" class of JW's tend to give greater honor to those who profess anointing. However, recent statements in the Watchtower appear to be discouraging that. The organization has to walk a fine line in trying to prevent individual members of the F&DS class from gaining prominence in the congregations, while still maintaining the absolute authority of the F&DS as a group.
- Is this class the only one that actually receives the emblems of the sacrament/communion?
Yes. And they take a purely symbolic view of Communion, so that they would see no actual presence of Christ in the elements, not even a spiritual presence as in the Reformed tradition. Those who profess to be of the "other sheep" class refuse the elements as they are passed among the congregation.
- What if one or more of them claimed to receive a communication from God?
They'd probably either be regarded as nutcases or disfellowshipped as apostates, just like non-anointed Witnesses.
- How does one become part of the Faithful and Discreet Slave leadership?
Years of faithful slavery and lots of brown-nosing.
- How is one expelled from that class?
One is not expelled from the class as such, but anointed Witnesses can be disfellowshipped from the organization if they violate the rules, just like non-anointed Witnesses can. Should that happen to an anointed Witness who is later reinstated, that person remains part of the anointed class. Only Jehovah knows whether the person has become so hardened as to commit the unforgiveable sin, and if the person has done that, Jehovah needs to choose a replacement anointed person so that the number of 144,000 doesn't come up short. Apparently this happens a lot, because new anointed seem to be popping up left and right these days.
Hope this helps. I may decide to use the above material (anonymously, of course) on the Q&A page of my website (www.dispelthedarkness.org). Hope you don't mind if I use your questions, but I think they are a good series of questions for helping people who are not so familiar with the JW's to understand this doctrine.