shutdown() will be added for dp3, however it will be upto the whoever runs the server to make it autorestart (there are scripts and applications which can do it for you)
DX Drawing functions are not in dp2, you need to wait for dp3 like it states on the wiki
Before dp3 is out, it is most likely that details of it will be put onto the wiki
My brother had that problem, so when installing i chose not to make a mtabeta account (because already registered one on mtabeta.com) and i just manually entered the info into his registry, details can be found here viewtopic.php?f=89&t=21435
MTA havent released the documentation for Lua yet, also the Lua for MTAVC is just a little project done by someone in the qa team and isnt made by MTA, however we did release a few tutorials ready for MTASA
http://www.mtasa.com/scripting.html