In the stock version of cubecart, you have to go through a registration process to complete purchase which does ask for quite a few details however you can easily add a mod which will make it ask for less details or remove the registration process alltogether which can be found on the cubecart forum. (link below). It takes a bit of getting used to but once you know what you are doing cubecard is really simple and versatile to use.
It takes a bit of getting used to the browser issues between firefox and IE as in it nearly always looks fine in IE but as soon as you look at it in Firefox, if you've done it wrong it can be all over the place. Only took me about a week to see where i was going wrong on this though so again not too difficult.
I knew nothing about cubecart about 6 months ago and self taught myself by looking at other cubecart sites, finding features i liked on them and then tried to do on my own site and if had any problems asked on the
cubecart forum which has loads of free mods and lots of helpful people to talk you through any problems you may have.
The template on my new site was made by myself yes.