This tutorial was very helpful. However, when I tried to copy/paste the code for easy mini, it kept shortening the code and it didn't show any pictures on my blog or sidebar. So, instead of doing it that way, I clicked on "off-site" under promotions in my easy shop. There, you can choose a widget that says "I sell on etsy" in a variety of sizes. Choose the one you like best, click "generate code" and copy/paste that code to a page or text widget. You won't be able to see pictures of your shop items, but at least you have a link to your shop that it easy to get to. I think the issue may be related to wordpress recently disabling flash player. I also noticed the same thing as some other people: when I went to add a page, it says text, not HTML. Not sure if that is related. This video was made several years ago so perhaps wordpress has changed a bit. Hopefully this helps!
The Etsy Mini in the sidebar doesn't work on my wordpress blog, either, & from everything I've read online, it looks as if it isn't supported in the way that you've done this, so I wonder how it worked for you!