My problem is that what I would like to learn and think I should be applying I am restricted from doing at most clients. This restriction is on time. Yes, I could do it in my own spare (sic) time.

I would like to spend a reasonable amount of time to learn the diagnosis/debugging features of SQL Server inside out. Including performance. I think that these are basics but are often overlooked but more often put in the "later, always later" pile.