It used to be that you could only discuss TARA in TWOP and the official AXN-Asia forums. Now, there are many more. They all have the something for everyone, including a site that's clearly not for the faint of heart.
But after making the rounds of the different groups, I have to say that this is the most in-depth, up-to-date and accessible. And because of your smart pursuit of spoilers, it's the only one that's ever referenced by other groups.