I had a look at the source code/snippet, and this search plugin does indeed use https and doesn't add any unnecessary query parameters, but does not query YouTube for search suggestions but google.
To query Google for YouTube results, one would have to add an additional query parameter to the suggestions query.
This add-ons does not work, it cannot find the installer or something.
Hopefully, you can fix it, thank you.
Edit: Clicking it several times finally got me to a prompt to add it to my search bar, but many times it would give me an error.
The addon is fully reviewed and OpenSearch compliant (there's actually no "installer", it's an xml file handled directly by the browser).
Unfortunately, sometimes the AMO site can be a little buggy (I believe I have traced it to a .js file here that users sometimes have problems with) and cause transient issues such as you have described. I am glad that you did manage to get things to work, though.
Does everything it needs to do with the added feature of SSL encryption added for flavor. I didn't even know about the search suggestions until after I installed it. I welcomed surprise.For the record, I'm using this from Ubuntu 11.04, so it's clearly cross-platform compatible.
i'm on Ubuntu 10.04 LTS and all i see when clik on "Add to FF" is an .xml(i try to dw your file and install it manually.I try to change .xml file extension to. xpi but no luck) file. In other words actually is impossible for me to install your plugin
Love your search addons. Youtube search works great, including search suggestions. Thanks!