Different entries in the plan cache, very likely the same plan form, but two different plan objects in cache.

The queries would have to be an exact text match to have...

SQL Server failover clustering or Always On Availability Groups? Your posts are not clear as to which you're...

Yes. The complete reverse engineer and rewrite of a crop modelling system,...

Only checksum = you have no idea if your backup file is damaged

Only verify only = you have no idea if your backup file is damaged

Both - you have...

Are you appending to the file when taking backups?

Ignore scan count. It is not the number of times a table has been scanned.

As for the high logical reads:

Large table

No indexes

Non-optimal execution plan

Poorly written query

Poor table design

Pick any one,...

Blocking? Something on that server has rows for november locked?

Error log will also tell you the login name used.

Depends

Are you talking about Always On Windows Clustering or Always On Availability Groups?

Steps 4 and 8 both invalidate/remove the cached plan from cache forcing the optimiser to create a new execution plan

None of the rest require sysadmin, and to be honest you probably shouldn't be letting an app make random login changes. It has no business doing so (and that would...

As long as, when the service restarts, the system database files have the exact same path and name and SQL has full permissions on files and folders, you should be...

Via windows scheduler? Via an application?

The other thing to think about is that the database is the unit of restores. Will you ever be required to revert customer 42's data back to how it was...

You can't.

A backup, no matter how many...