I have a similar idea of a minimal html browser, which was dismissed by the gemini authors. Should be reasonably doable if you don't implement all web 2.0. No css - user decides appearance, no javascript - it would require full web 2.0 anyway, and a bit of webcompat, start with <div>, <p>, <a> and there you go.
I would not want a simple browser to replace gemini, but I would be happy to use a simple web browser in addition to gemini. It would be nice to only have to fire up a big bloated real browser for doing banking and such things.
