First of all, i am gone say that so far this project seems to be a success and the entire developer team put a lot of effort into it to rewrite this awesome game which we all love so much, for us, with us, for themselves.
It's a matter of fact that the last release Version, which was 1.0, seemed to a great success. People accepted it, Let's player started playing it, promoting it on Youtube etc...
It is also clear that a release version usually should go through a testing phase, a code review, which lead to major bugfixes and so on. But this is something a small Opensource Project maybe not able to handle, because it requires much more resources, more people to review the code etc.. So you are basically stuck with bugs which get reported from the people who play the game. This has obviously happened as the difference between the newest nightly and release 1.0 in terms of fixed bugs and stability of the game has been greatly increased (i so far never had any crashes from openxcom itself, mostly Mods not finding files (case sensitivity and so)).
And since it is now nearly a Year since Version 1.0 has been officially released, i would recommend implement Missionsite stuff, fix whatever bugs there are (which are known), fix them. Make a big anouncement release it as Version 1.1,
not only Modders would profit from that but also a load more people which give free advertisement (the let's players), which tend to go for release Versions, because not anybody is willing or able to compile code itself, or install the required libraries.
Keep working on the TFTD support, release your changes over the nightlies and when you have reached a state in which the basic features for TFTD are implemented, do a new release. Fix bugs over nightlies, so people have the ability to upgrade whenever they like.
I mean come on you've done a great work here be proud of it and make it known!
People want this game, give it to them