1. I'm not sure how secure forms are but if you're not worried about security then implement it in C2, I say.
2. If you use a local webpage then you'll have to reupload the entire game each time you make changes to it vs. uploading just the webpage to your server. Otherwise, a local webpage should work fine.
Others may know better than me so see what they say too <img src="smileys/smiley1.gif" border="0" align="middle" />