On Hans's suggestion, I've been working on a "dense" character encoding that does away with combining accents and extraneous symbol-like characters in favor of fully accented characters.
This encoding is sort of based on the EC encoding, but adds (to the best of my knowledge) support for Romanian, Maltese, Welsh, Lithuanian, and Latvian.
The punctuation that I kept was "typographic" in nature, that would fall within a normal text flow, especially those affected by ligatures and/or kerns. The typographic symbols were left out, including monetary symbols. I reckon these could be called as symbols from another encoding.
The general intent here is to have strong support for (latin script) modern European languages, in the context of Unicode input. I concentrate on letters, in order to give as good kerning as possible with a 256 character subset. The letters are fully composed, to help hyphenation within TeX. Note that the encoding can't handle general transliteration or other "academic" uses.
So with those goals in mind, does anyone notice their favorite *letter* missing? Is there essential punctuation missing?