Is it possible to attack a metal mine/oil well from an allied metal mine/oil well? Like if the metal mine/oil well is owned by an alliance member... could you still use the mine/well as a normal outpost if you don't personally own it?

I believe you can't, since no one can attack from any resource op.

You may not attack from Metal Mines/Oil Wells, if your alliance has a resource outpost, yes you may use it as a outpost in means to transport units.

Thanks for clearing that up for me, guys. I appreciate it.