Hello Mildred, It sounds like you're trying to reinvent the wheel, and I can understand your desire for it (although I don't share it at all); but it also sounds like you haven't looked deep enough into the existing tools:
I still plan to eventually move to LuaTeX when it will recognize unicode characters.
LuaTeX interprets its input as UTF-8 byte sequences, and handles characters by their Unicode code point internally. Thus, it does recognize Unicode characters perfectly well; you seem to be expecting something more, but you should describe it more precisely (and maybe not on this list).
The other reasons being that I want to learn low-level TeX
If you want that, you should start by reading the TeX book and the LuaTeX reference, which are perfectly well documented. There is simply no way out. Arthur