[madoues]

I've made myself curious. Mike, if MS imports a CP that, for example, was typed using D chords, but has a {key: E} directive, how does it handle this? Does the {key} directive trump the actual chords in the file, or vice-versa?

Yes, that is a good one. It will display the chart in the key of D but if you want to change keys,
the pop up window to change keys says it is actually in E. 
So if you want to play down 1 full step to C for example, you have to set to the transpose function in D.
I believe this is how it works. It can become confusing, especially if you have minor key directive.
That is also one of the reasons I may remove all my minor key directives and just put the corresponding major key.
Now, say you have a {Capo:#} directive on top of this, that one is a doosy.  

However, MS can't be responsible for correcting for mistakes in pro files,
after all, some songs don't necessarily start or end in the same chord as the key directive.
I prefer it this way, just make sure the pro files are correct.

my 2 cents...
Dan