I wonder how much left there is of ESH in 2.5M2… for instance, I still use org.eclipse.smarthome.* for logging, still works but isn’t that expected to be or become deprecated ?
Is there any official list of changes since 2.5M1 other than the build notes at https://ci.openhab.org/job/openhab-milestone/7/?
That is likely the only list. It would be difficult to condense accurately, IMO.
Your other questions pertain more to future plans.
2.5M2 did not primarily address any issues that occurred in 2.5M1.
I suspect the work will be to address those issues ( & any new ones) and then release 2.5.
It is already past the goal release time and there have been many changes.