I've spent a lot of time building online store with SCD & SCC, but now realize that it has to be made responsive.
I've have heard about others using css to modify their SCC shops to make them responsive.

I haven't done much with css coding yet, so my questions are: -

1.) How difficult is it going to be for me to learn enough css to make my current shop responsive?
OR 2.) Is it going to be easier to start a new shop from scratch?

I would be interested to know this too as I would like a responsive shopping cart so it will rank with Google.

Is CC going to release a responsive cart any time soon?

That is a good question. I have been looking at other products with a view to getting out of Shopping Cart Pro. There are many good competitive products out there, however I have a "Must Have" list and so far none have ticked all of the box's.
I like coffeecup because it looks and behaves as if it was written by business people not tech people and that is where other products fall short. So when is Coffeecup going to release a version of Coffeecup Creator Pro that is:

Responsive, and

contains mark up required by Google.

Kim