I'm afraid many of the bloat and performance issues on normal browsers are because of cross-platforming. While the idea of a single source working on multiple platforms is great in theory, the reality is you take a huge hit because the code is a "jack of all trades, master of none." Abstracting things like window routines and widgets puts a huuuge penalty on any software. It would destroy the singular purpose of the project.
Re: Skip to Chromeless core - to become crossplatformed !!!