Strictly speaking Michael, aka Mythos_Ruler, is the Project Leader though http://play0ad.com/about/organization/ Has some more information on the more formal parts of how we're organized, but apart from that it's pretty democratic/community driven
For Windows, you never need to compile. As compiling on Windows isn't easy, we do it for you when it's needed. For other OS, if all changes were in the binaries directory, you don't need to compile it again, if there were changes to other directories, you need to compile it.
That depends on what changes have been made, if only .dae files, png files, XML files and other art files have been changed since your last update = no need to recompile, if js/json files have been changed = most likely no recompile needed, if .cpp, and .h files = you have to recompile.
I would say there are two main reasons: One is respect, they have said that they want to do this as a mod, so then it would be rude of us to just ignore that and include it anyway. Especially since they have a good reason: to show what's possible via modding and inspire others to create mods of their own Two, there is no reason to include a half-finished civilization. Once it's finished there might be reasons to consider including it in the main game, but not when it's just a few units and buildings and objects.
Well, I won't hold you back in terms of contributing. In fact everyone is allowed to join the team, if he wants to. You just have to contact NoMolester (the mod leader) and he will take care of the rest.
I am asking because I might be interested in contributing models and textures. Great mod to play for Mount&Blade: Warband - Vikingr http://forums.taleworlds.com/index.php/topic,286569.0.html This mod really goes into details of the units for Vikings.
how many wood I will gain by cutting the christmas tree? It will be possible to loot santa for some metal and stone ? it will be possible to eat rufus for some food ? since it's 0AD we will see jesus birth on a sand map?