I was fascinated by those rules, tsuwm, though I've never been in a Scrabble club. I enjoy playing when I get the chance, but I don't like to play for points. To me, the 'point' is for all the tiles to be (legally) used. If they are, then everybody wins.
For me the point is to win the game and at the same time show how clever you are by making the most interesting, bizarre and disputed words on the way, making two three or four words at once with obscure two letter ones, and getting all your letters out in one go at least once during the game!
Me? competitive?? Not me!
Seriously, though, I'm not into competition scrabble and arguing over what dictionary is allowed, etc. I just play between friends and family, and we use whatever is on hand and/or whatever words players can convince us really are words.
On the issue of greek letters, they are allowed because they are used in English for symbols. I wouldn't normally allow the spelling of English letters because that is not standardised, and there is no reason to spell a letter. And is Zed allowed in the U.S. and Zee allowed in Britain? And is it ef or eff? el or ell? em or emm? en or enn? and how do you spell 'q'? kew? They are not really spellings, but phonetic representations of the sounds we make when we say the names of the letters. Z is really spelt Z.
