After a few small hiccups, it has finally worked, and I'm all psyched to announce that now, finally, my whole site is now running under the SSL protocol, as evidenced by the friendly green lock you should be able to see in your browser address bar.
This blog, by the way, was the main cause of the hiccups, and took most of the migration work - everything else was settled with three checkboxes checked, so just a very few mouse clicks. The blog, however, had to have URLs changed, and there was a remaining issue kindly and quickly fixed by support (thank goodness for IT support people, magicians with keyboards). So for now, everything is running, except one of the Wordpress plugins is not playing nice with SSL, it seems. So for you now no longer get a fancy lightbox to look at pictures.
While blog reading might not be enough of a security issue to warrant a few hours of work doing the switchover, the shop surely is. As of now, I've not offered payment methods that require me to save payment data, or you to submit your data to my server, due to not having SSL. But now, to my great delight, everything will be transmitted safely and securely encrypted... and this also means that eventually, I might be able to implement direct paying possibilities. That's something for the medium future, though, as credit card options or direct bank transfer needs some good research into options and costs before I can actually consider any of these.
For now, I'm happy that everything seems to run smoothly again - and shall celebrate for a bit. Yay!