first of all, Im italian, so my english is not where i shine... that being said:
1. size is not an issue as all of your classes, and no, no wasteful features, I think however you could add in the future the capability of loading an external SWF and extracting the font embedded inside making it available to use within the loader, that would be AWESOME!!!
2. No, yes,yes.
3. Im not crazy about flash events and the way they "communicate"... have you seen this project yet? http://flashblog.robertpenner.com/2009/09/my-new-as3-event-system-signals.html... but again, with a little help from a good AS editor constants names are just fine!
4. Ops, I wrote it in the point N.1, sorry, I couldn't wait!
5. Yes, the day I'll stop programming in AS3
Keep up the good work!!
