There is another way to do this which solved my "alpha" problem:
go to: edit -> special characters
This will bring up a box of many special characters divided into several categories, one of which is greet. You can choose the symbol you want and click insert.
Though the keyboard shortcuts are quite useful (I use the one for µ everyday), I couldn't find one for alpha.
Notably, the "edit -> special characters" menu option seems to be in most apple software in Panther.