I found it immediately annoying and switched her out as soon as I got the next companion.

Only if you are going for the 'achievement'.

The Datacrons. I don't consider +30 to primary/secondary stats to be optional.

When you say it's up to date, you mean you installed that specific DX9 redistributable?

Have you tried installing the DirectX 9 update? http://www.microsoft.com/download/en/confirmation.aspx?id=8109

I noticed something about the heat dissipation rates... Fast - 5 Moderate - 3 Slow - 3 Very Slow - 2 Is that how it's supposed to be? Doesn't seem right.

Heat dissipates more slowly as there's more of it. It's basic physics.

There is a loading screen tip that says it affects the results and the duration.