Excellent list and great set of suggestions. I'd suggest an exchange, already covered by others. Yanke the DTA and put PowerShell up in its place.

The DTA is just way to shaky in its performance to be truly useful. I've had to run it during Premier Support calls with Microsoft and the suggestions have either been useless or harmful. I'm sure there are instances where it helps, but I haven't been able to see them. And that, despite having to write about it for my book. I tried and tried to get it to suggest useful indexes, and on queries that clearly could have benefited from an index. Queries that had missing index information in them, the DTA just couldn't find a good index. It truly stinks.

More and more I'm finding uses for PowerShell, specifically with SMO, for management & development on SQL Server machines. I'd say that should be one tool that gets added to the standard DBA toolbelt.