I think it is best to work with the raw (at least that's what I do). If I can't do a calculation by hand (or with excel or a calculator) then I can't expect an Arduino to do it. Also I need the hand calculation to check my Arduino program is doing the correct thing.
In your post #16 you report:
Accelerometer readings
Average : 9.946030616760253 //This is the "g" that I take away from the accelerometer readings to find delta Acceleration
What are the units for the number 9.946030616760253 ?
What would you do with delta acceleration?
Velocity = V(inital) + a * t So to get velocity you would (perhaps) take 10 readings in 1 second (for all 10). Then multiply the average acceleration * 1 second for velocity in whatever unit system a was in.
The next 10 readings will result in a new velocity that will be added to the above velocity result .
etc
etc
etc