I wasn't aware of the existance of that fork. But to use it, you could clone it, or download it locally, and then drop the TinyMceDeluxe folder into the Modules folder of your Orchard project.
The way I work with Orchard, I always set up a clone of the main Orchard code locally, and then pull in the source code for any modules I want to use into the Modules folder. So from that standpoint, yes, you'd have to compile it yourself. I think it would
probably work if you installed from gallery and overwrote the files with the changes you see in the "FullFeatured" fork. I haven't tried that method but it should also work. I couldn't help troubleshoot if you go that route though.
So here's what i'd do (these steps are off the top of my head, not meant as a runnable script, more as a rough guide of steps to follow):
hg clone https://orchard.codeplex.com
myOrchardProj ## replace the url with the actual codeplex Mercurial repo URL)
I'd also set up the TinyMceDeluxe folder as a sub-repository, but that's another topic.
Then, if you needed to, you could make even more customizations to any of the files to customize the TinyMCE editor even further. Then compile, and deploy using the methods in the main Orchard documentation. Hope this helps!