Item #3 is the most often mistake I run into when taking over AdWords campaigns. Some people do not even know the difference between the three match types (four if you count negative keywords). Bidding only on broad keywords is a sure fire way to burn your budget.

I would also add to this list the fact that all campaigns by default are opted into the Content Network. I think it is a bit of a shady tactic by Google, but it is something that needs to be addressed right away.

Some nice tips, especially agree with your first point about relevancy. I’ve found countless examples of PPC ads that don’t include the user’s keywords in headlines or descriptions:

http://www.alanmitchell.com.au/techniques/relevancy-the-holy-grail-of-ppc/

Also agree with your and third point on over-use of broad match – exact and phrase match can be extremely powerful if used effectively.