Hi, im working to answer all this issues.

one of the biggest later was the shipping methods one

for that i coded something that will try to generate $this->mc_shipping_methods and $this->mc_shipping_methods_names using Zencart's Shipping class

here is the link

http://demo.globant.com/~brovagnati/tools/ -> Zencart Automatic Shipping Method Generator

Have a look to the README. But should be a unzip and work...

any doubts please feel free to ask.

ropu