Well put Jeff 🙂 You had mentioned most of the items that I have been through last 10 years. After few "told you so"; I am now being called in few applications in the design phase. Good improvement.

I would say, DBA's has to be involved right from the design phase or the project kick off phase. Most of the instances, I had been called when there were system slowness or not working, but in my company things are changing a bit after few years of shouting:)

DBA's need Wiki's so we can point out to others of standard best practices as well as recheck them when needed.

Addition to best practice list

Out of gate monitoring on the entire system and SQL Server, immaterial of the critcality or availability needs

Retirement plan for server