1) The presiding overseer position still exists but it has been renamed as "Coordinator of the Body of elders". Most JWs would just say "Coordinator" for short or pronounce the acronym CoBE.
2) I don't think that Watchtower takes too kindly to any suggestions for improvement or correction from rank and file publishers. But if you insist on having yourself put under scrutiny by the elders in your congregation and getting yourself thought of as being prideful, murmuring, presumptuous, spiritually weak, etc, the address to use is the address of the New York headquarters. You can probably find that address on their website in the Contact us section or on the inside cover of a year book.