I think that the adding of characters actually improves readability, because it's much easier to read
F R U R' U' F'
Than
FRURUF (I don't have those special characters on my keyboard)
In any sense, please do not try to change the current notation. I like the guide, but the notation is much less desirable than the current notation for the following reasons:
1. Hard to read.
2. Hard to say out loud, "R prime" is much easier to say than "R with a dot over it" or "R inverted"
3. x, y, and z rotations are easily distinguished from regular moves. And a notation for rotations in respect of faces is already in existence, like this, [r]
4. There simply aren't any shortcomings to current notation that have been remedied by yours.
Nice guide though! Good to see new members contributing!