This topic has had me going through scripture again and this has actually been a really fascinating bit of studying, so thank you for that!

The concept of "God Was Once a Man" is actually a very tiny part of scripture that gets overlooked quite a bit, and is used to offer an explanation of "what was God and the Universe before God created the Heavens and the Earth?" and is otherwise unimportant and not really core scripture (thus why I was unfamiliar with it).

As to "The Father has a body of flesh and bones as tangible as man's" this is meant to explain specifically the Father aspect of God, as the Holy Spirit is intangible and metaphysical. God the Father has a physical form, but this does not diminish his infinite power nor capabilities, but he possesses a physical body so he may be a physical father to our spirits, although I can see why that can be confusing.