You might want to explore putting this into a columnstore index, see if that helps. It really depends on the types of queries being run against it, but pivoted storage,...

Have you tried capturing sql_batch_completed and rpc_completed (maybe even toss in module_complete) using Extended Events? That's usually what I use.

Monitoring and observing the system will certainly tell you more than I can remotely. The one thing I'll say is that doing a differential every two hours, those differentials at...

No way to say for 100% certain without at least the execution plan, but, best guess, those LEFT functions on the columns are going to lead to index scans. Same...

System processes and other threads.

Why would you immediately run sp_updatestats on slow...

No. It's not the same as measuring threads. It's just the users connected to the database. Generally, there's probably a 1:1 correlation a lot of the time. However, it won't...

The best way to monitor this in 2012 would be using Extended Events. However, it does require that you set it up and maintain it. There's nothing automatic that does...

Also, you have to have a way of identifying the user. This means one of three options. One, everyone has an independent login on the database. Two, everyone is using...

So, collective wait stats, everything since the dawn of time, are somewhat interesting, but not terribly useful really. They will tell you where the principal waits are on your system...