a) provide downloadable script package. Make it simpler. Separate CSS code into CSS file and JavaScript code into js file
b) provide means for having menu separators, disabled menu options, options which do not have active link
c) provide possible use of optional image for each menu option
d) provide simpler CSS, with better hierarchical settings provoding that options in deeper level of menu inherit looks from their parents if there is no specific look defined for that option.