Hello
It is very interesting indeed.

Is it already available for anyone to create their own website using decommerce? what would be the steps to follow?
I think your major challenge here is to get merchants to actually build their website in here (+customers).

I think it would be easier to start and grow to create a marketplace (Amazon for Crypto) with the same idea you have (Crypto payments, censorship resistant,..)

Customers > people that want to spend in crypto rather that Off Ramping to FIAT.
Sellers > a solution to start having available products from day 0 would be to bridge to Amazon (or Aliexpress...)

so you can add products in your site that are available in amazon and at the moment that the customer buy them it automatically buys on amazon and sends the order.

with some time, you'd be able to onboard real sellers.

if you think it is interesting and want to develop, happy to help