1) What do you take lower parts of the earth to mean?
Where do most people understand hell to be?
Were you confused by the use of the word hell?
2) So what about
the communion of saints,
the forgiveness of sins,
the resurrection of the body,
and life everlasting.
did you think disagrees with "everyone who believes in him may have eternal life"
It seems to me you are swallowing camels and straining gnats.
1) As you probably know, there are two very different understandings: Jesus went to Abraham's bosom, a compartment of Hades, and Jesus came to earth. In the first view, Jesus gave the gift of perfection, allowing them to enter the third heaven. In the second view, Jesus gave the spiritual gifts to born anew believers. I believe the first view is correct, but either view may be correct.
2) Hopefully most believers know about Hades and Gehenna. If people do not know that at least some of our early translations, translated both places as if they were one place, shame on those who discipled them.
3) I always object to the use of Hell, as it represents false doctrine.
4) I have no idea what others might say is the "communion of saints." Every born anew believer that ever lived is a "saint" set apart by God into the spiritually body of Christ, the one loaf of 1 Corinthians 10:16-17. I believe in the fellowship of all those called out of darkness into Christ, as spiritual siblings of each other and of Christ.
5) I believe the forgiveness of sins is accomplished by the washing of regeneration, and NOT by imputation.
6) I believe everyone believing into Christ will not perish but have everlasting life.