peace truthsearcher, all,
Your questions/thinking is quite a common reaction, i.e. it is thought about and often asked by others.
Since I have been a forum member for almost 10 years and have been studying Quran for roughly the same time, I will share my thoughts.
Firstly, please bear in mind verse 3:7. This seems to be an under appreciated verse. It's message is very powerful. Please ponder upon it.
Secondly, please do not compare like with unlike. For example, you list quite a number of different views, but be careful you do not confuse the wheat with the chaff. If you ask yourself: how many of those views actually have a detailed article behind them? You will suddenly find the number of variant views reducing dramatically.
Now, once the list of variance is reduced, ponder upon what the differences would be in a practical manner. Usually, the variance, whilst still there, is again reduced.
And lastly, from my studies of Quran, it does seem it placed an emphasis on unity on the core beliefs/laws. If a society has these, how relevant are the rest? If your next door neighbour is law-abiding and righteous but believes one must do cartwheels and handstands in their timed salat - how much does that matter? What if they are law-abiding and righteous but believe their cat is their God - how much does that matter?
I liked the reference that you gave in 3:7 and it brought to mind something else, if I may add:
God, there is no god except He, the Living, the Sustainer. No
slumber or sleep overtakes Him; to Him belongs all that is in
the heavens and the earth. Who will intercede with Him except
with His permission? He knows their present and their future,
and they do not have any of His knowledge except for what He
His Throne encompasses all of the heavens and the earth
and it is easy for Him to preserve them. He is the Most High, the
Only when Allah (swt) is ready is anything revealed to us (we are allowed to understand).
And then as I re-read 3:7, it really hit home for me.
He is the One who sent down to you the Book, from which
there are firm revelations; they are the essence of the Book;
and others which are similar. As for those who have a disease in
their hearts, they will follow what is similar from it seeking to
confuse, and seeking to derive an interpretation.
But none know
its interpretation except God, and those who are well founded in
knowledge; they say: “We believe in it, all is from our Lord.” And
none will remember except those who possess intelligence.
All this nit picking over how often should we pray, should we bow three times or four, how many days are we really supposed to fast? I can't speak for anyone else, but reading that ayat (did I use the right term there?) made me realize just how shallow my worship has become.
You are right...it is a very powerful verse.