As already stated, this is a one-way upgrade. You can fail over to a higher version but you can't fail back to a lower one. As long as you have...

This is in the 2008 forum, is it meant to be? If not, which version of SQL will you be using? You usually need a cluster.

Yes, don't worry about this. (I would personally cap Max Server Memory at 26 GB on that server, but that's within tolerance.)

Could you not just do a backup and restore instead?

An older version may well be easier to use in this case. Try it with both if you can. I've connected to SQL 2005* with SSMS 18 so it can...

Sometimes there is some useful information in the installation log files. The default location is listed here:

https://docs.microsoft.com/en-us/sql/database-engine/install-windows/view-and-read-sql-server-setup-log-files?view=sql-server-ver15

Yes, it should be ok. The only thing I can think of that might be an issue is that if there is any mirroring in place, sometimes it's not visible...

Ah, ok :-).

In that case you need to put the instance name in here (instead of MSSQLSERVER). Also the port will probably be different:

/INSTANCENAME=MSSQLSERVER

In addition to what Michael L John has already covered, if you use a secondary replica for reporting, there's a requirement to license that replica as well as the primary.

Also...

Is it a named instance?

Have you checked that the endpoints are in a STARTED state?

select * from sys.endpoints

I'd go for 2017,  personally. Don't bother with 2016 in that scenario.

AndrewL65, do you mind me asking what you're finding interesting about it? (Also, is it true that the cardinality...

Here you go.

https://www.brentozar.com/archive/2018/06/job-duties-for-database-developers-development-dbas-and-production-dbas/

How its written for DBAs because they can't code

Charming. I dislike SSIS, and try not to use it. Fortunately I've rarely needed to.