I finally gave up on AutoHotkey as my main keyword expansion tool on Windows. The biggest issue I had was escaping characters (like colon, curly brackets, hash, etc.). The next issue I had was when I wanted to enter longer expressions with returns and tabs. Not only was escaping characters a nightmare, but typing a tab character produced unexpected results (sometimes doing nothing, other times exiting the form).
So, after trying all the programs available for Windows, I settled on PhraseExpander. I've been using it for a few weeks and I'm really happy with it so far. Not only is it already a great program, but I emailed the developer about a few issues/ideas I had and he was very responsive and open to suggestions. He said I should see some of my suggestions in the next release.
I've also started using keyword expansion to access commonly used help info. So, for example, I use the keyword "gwm" to expand to "Get ( WindowMode )", but "gwmh" expands to:
Get ( WindowMode )
/**
* 0 for Browse mode
* 1 for Find mode
* 2 for Preview mode
* 3 if printing is in progress
* 4 (FileMaker Pro Advanced) if evaluating the function from the Data Viewer and the current window is in Layout mode
*/