Thank you for sharing your work. I learned from reading it.
For example, Opera 12 (Presto) has full modern DOM support with .createElement and such, but I doubt your framework would work with it?
There are hundreds of browsers and engines out there, and I want to support them all. Would your framework degrade gracefully in a browser you've never tested before?
Also, how do you deal no-JS users? I read through the documentation, but could not seem to find one?
This is a noble and audacious goal, but I suspect that it would either take enormous resources, or the least common denominator approach.
OTOH supporting, say, the 3 major browser engines that serve > 99% of the audience is sort of achievable, and also practical.
b) I believe the remaining 1% matters, perhaps more than the others. (See wheelchair analogy.)
c) Yes, it does take a least common denominator approach at first, but you can build a lot on top of that, carefully, without upsetting even such classics as Netscape, Mosaic, and IE4.
Would you say that one developer working part time for a couple of years is "enormous resource"?
IE4 had an early DOM but it was different from the current one, and JS syntax was different too.
Writing DOM-modifying code that does useful things on IE4 as well as on current browsers is possible, but requires a lot of extra code and testing for little gain, and will encounter browser bugs if you do anything complicated, so you can't just drop in a thoroughly-portable framework, you need to test as well.
If what you mean is you'd like graceful fallback to a decent non-JS page on ancient browsers, that's doable, but then it doesn't matter if the JS framework only supports 99% of browsers. Just make sure to disable the framework on browsers too old to use it. (You'll still have a hard time with CSS on Mosaic.)