Ok many of the syptoms can be explained just because it is a DC looking at itself for DNS, typivally a DC which looks to itself for DNS will take upto 15 minutes to boot up with most of the time spent on applying computer settings, the reason it does this is simply because it is looking for itslef but cannot find itself because it has yet to start, its a catch 22, but DC's are not meant to be frequently restared.
You need to concern yourself also with events and issues that appear once the server has succesfully restarted.
So points 1, 2 and 3 and 5are normal after a restart, however after any warning event you should then see a successfull service start.
Once the server has started UP and settled in are you have issues with, does dns not work has the service still not started?, can users not log in? you need to establish what is an issue and what is normal.
Clear out and saving of all the event logs after the server starts, then focus only on new events (which there will probably be none)
"In order for the directory service to consider itself synchronized, it must attempt an initial synchronization with at least one replica of this server's writeable domain. It must also obtain Rid information from the Rid FSMO holder."
This is worth looking at, can you check the staus of the RID master role, maybe move it back to the other DC and then back again, also let it settle in a while after each move.
