True religion, which is one?  

If there is a true religion I'd say buddhism comes closest.

You are asking a very interesting question and you have also done a lot of research.

I would like to comment a little. The Catholic church was founded after 300 after Christ. Jesus never spoke of priests and popes, all the christians were brothers and sisters and nobody got paid for preaching. The first christians had elders who taught in the congregation and took care of it and none of them was paid either. They never used pictures and saints in their worship.
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Charles Taze Russel actually never founded a religion. He started to study the Bible with others, since he saw that the churches around them were not following what the Bible teaches and even more often did the opposite.

Charles and his friends called themselves Bible Students and started publishing what they had learnt. The Witnesses nowadays have continued to study the Holy Scriptures and leart a lot more things that Russel did not understand in his time. I went to www.watchtower.org and made a search with the words russell and truth and found some interesting information there.

If you wish to read the Bible in modern English, you will find it on the same homepage.
You are welcome to write to me if you have questions.