Very helpful Bayu, this was exactly what I was looking for.
Only thing I thought was interesting.. in misconception #2 it says "if a non-head extent member goes down, you won’t be able to access the VMs whose virtual disks have at least 1 block on that extent." We had two 1TB LUNs with one of the extents as showing offline. There was 50GB free on the datastore, meaning data must have been on the offline extent.
We were able to create a new 2TB datastore and sVmotion everything off. We were all curious as to how everything stayed up (not that we are complaining).