Reverend,
As long as whatever a person practices brings them closer to God, what difference does it make? With respect, religion is a personal choice. What works for some doesn’t work for others. It sounds like you’re open minded about other religions and acknowledge with your list of six qualifiers that at the core, world religions are more similar than different. If someone chooses their own path yet still follows the teachings of Jesus, how is that a bad thing? Jesus loved and welcomed all, yet I don’t know of many churches that follow this example. Jesus said to love your neighbor. He didn’t qualify what kind of neighbor. He said not to judge others. Yet so many churches proclaim “non-believers” are going to hell for worshipping differently or practicing lifestyles which have been judged as unacceptable.
God loves all of us, and if more people and churches would leave the judging and condemnation to Him, the world would be a much nicer place in which to live.
Go with God, my friend.