Hi Reserch. We have quite a number of elders on this site and we can at least put a couple of your questions to rest.
The elders manual (there is also one for C.O.’s and Branch level} is called “Shepherd the Flock of God” you can find a copy of it Here
What irritated me is that during the A.R.C. Proceedings, Watchtower employed an ‘expert Witness”(who was no such thing) called Monica Applewhite - yes a woman, and a Catholic - who was allowed to peruse this manual at her Leisure, that elders wives are not even permitted to ring bind for their husbands, let alone see it.
Double standards?
And yes, Watchtower does keep information on file, even after you are deceased, on everyone. The blue envelopes you refer to are definitely used, most notoriously in cases of CSA. Please refer to the “Shepherd” book for further info.