How about supporting functions like ABS as EXP in a better way than just as a function name.

The url rewrite has been implemented. Such that if you use the 'edit' subdomain then you'll be moved onto the equation editor. As in

http://edit.codecogs.com/gif.latex?sin(x+y)

http://edit.codecogs.com/gif.latex?a^2+b^2=c^2

http://edit.codecogs.com/gif.latex?\sqrt(1+a)\euro .