Hi, and welcome!
You can get more detail on my experience here: Snapmaker 2.0 Initial Calibration Settings / Experiences
Others have their own posts.
Don’t forget about linear advance, that can explain some of your issues.
Unless there’s a new extruder gear design E216 sounds way too low, in my opinion. I don’t disagree with your measurement of 11mm extra, just saying that sounds weird to me.
If you changed from 100->95.8 flow because of the vase wall, and that causes underextrusion elsewhere, then change it back. Wall thickness is less important than overall quality. 4% change is huge.
Double check your actual filament thickness. Make sure there’s no clogs, even partial, in the nozzle.
Your stringing tower seems reasonable. I wouldn’t worry about that until you get other things dialed in a bit closer. Retraction is less important on that than Z hop, which definitely should be enabled.
You have quite a lot of elephant foot, your Z is calibrated too close to the bed I’d guess, bump your Z offset up 0.05mm and try the first few layers again.
Your temps sound reasonable. I had the best luck with 205, but 200 is probably close enough if you’re happy with it. I think 205 was a bit shinier of a finish for me, and had a bit better layer adhesion. Make sure and pull apart/break a few tests to ensure the bonds are strong enough for what you need.