Yes CS does support different images for thumbs and main product images,
You can add a main product image which will auto-generate thumbs for the same product or you can add both your thumb and main images seperately
Google Base feeds,
From memory CS is improving their bulk export methods to improve Google Base feeds. Please don’t quote me on this one as I’m not 100% sure.
Editing the code for a different look, yes you can and you will find many.
such as example is www.notsounknown.co.uk. Obviously heavily modded.
Customise the layout on the category/subcategory pages,
I’m not 100% sure what you are looking to modify, at present you can change the amount of columns and rows to suit. Obviously if you have small thumbs you can accomodate more per screen size.
You can use included shipping ‘gateway/providers’ (I use Australia Post).
Users will have products shipped to their default billing address or for every order can specify the destination address of that specific order.
Non-Product pages… If you wouldn’t mind elaborating what you require specificall.
CS currently searches by product name only, advanced options are available to the user. ie [url]http://www.southeastauto.com.au/index.html?target=search[/url]
Hope this helps.