You are totally correct but still totally wrong and you can thank your teachers and classical physics
You sort of reach the right conclusion in (12) after a couple of wrong turns. The problem is acceleration is defined, as are all things in classical physics static universally and global.
You then switch to GR curved spacetime without changing your definition of acceleration. The classical physics version of acceleration is totally ambiguous and meaningless in the GR framework except on a case by case conversion.
When you look at Bill S standing on the earth, you will conclude the same that gravity is accelerating you towards the ground using classical physics
Definition problem again .. redefine acceleration properly to fix it
https://en.wikipedia.org/wiki/Proper_accelerationIn relativity theory, proper acceleration[1] is the physical acceleration (i.e., measurable acceleration as by an accelerometer) experienced by an object.
If you can't measure an acceleration you aren't
Don't mix frameworks as you can't, the definitions of spacetime differ and you will just get confused. Your statement (12) is correct in GR because you can't measure any acceleration with an accelerometer not because of any classical physics calculations. It is true by definition in GR and requires NO calculations.
GR is not an addition to classical physical physics it redefines everything. I am going to suggest you put the word "proper" infront of terms when you wish to use GR/SR so you remember it's different to it's classical physics counter part, so proper time, proper distance, proper acceleration etc.
So in classical physics you standing there you have an acceleration of 9.8m/s towards earth. In GR/SR you have a proper acceleration of 0m/s and it doesn't really require any explaining although countless webpages seem to want to try and just confuse people. It's that way because the frameworks define it that way ... the end !!!
People get fuel consumption of 1 gallon per mile does not equal 1 litre per kilometre yet we can't seem to get them to understand the above. Just because GR/SR gives different answers to classical physics nothing is wrong the unit definitions aren't the same.
All of the above is also the answer to the other problem with speed of light you were playing with and I was trying to get you to self realize. The speed of light in relativity is BY DEFINITION the same to all observers and here you were talking about different speeds of it without considering that was just from your assumption or inferring from your reference point. You were doing a Dave Profitt and going with your observation as a global truth ... try putting yourself as an observer where you see it slowed. Remember measuring or seeing something only ever makes it true from that reference frame.
What I might start doing is when you mix classical physics and relativity just simply prompt you with "Does 1m/g = 1km/l" as a reminder.
So your two problems are true by definition and can only be equated on a case by case basis with different adjustments under classical physics. Why ... because spacetime is static in one framework and relative with global zero frame forbidden in the other. There is no simple identical conversion between the two frameworks, in all situations that will hold.
