Would there be anyway to replace the built in agenda with the PI Today plug-in? I absolutely love the way it works with my Pocket Informant. Here's a couple of sites if you haven't ever heard about it.
http://www.pocketinformant.com/TodayPlugin.php
http://www.deje.gmxhome.de/download.html
Any info about how to do this would be great, if it can be done.
With TodayPlus, there really isn't a "built-in" agenda. It's extraordinarily flexible, and there are few things you can't do with it. Just look at the various skins (mine excepted) that available here, for examples.
If you find a skin that mostly meets your needs (assuming slider.txt doesn't), perhaps you can then indicate specifically what it is that it doesn't do, and either someone may be able to help, or a new Feature Request may be born.