Can I actually contribute code to the CI core?

[eluser]Narf[/eluser]
Follow the style guide and if the code is good - it will go in. New features usually require some discussion though and might get rejected.

Latest code is in the develop branch and that what you should base your work on. Make sure the bug isn't already fixed in there as there's an enormous amount of issues that are already fixed in it.

Many of those pull requests that you've mentioned have gotten outdated due to their authors not following the above pointers or simply not caring to update them. As you understand - that's beyond our control.