It's great to hear from a fellow veteran of the Minecraft hacking community.
I do remember WeepCraft. Before I started developing the Wurst Client, WeepCraft was actually my favorite. It was so much more practical than the purely PVP-focused clients of the time.
FlyCoder had quite a presence, I remember one time when he joined the IRC and the chat just exploded with messages. If memory serves right, his MC name wasn't actually FlyCoder, instead he had a distinct name which would change to FlyCoder in the WeepCraft client.
I don't think I ever posted on WeepForums, but yes, I do recall when it got mysteriously shutdown. There was this strange message suggesting he got arrested or something along those lines.
LeakForums, I assume, is the other community you're referencing. I only joined because someone created an impersonation account of mine. But there are a couple of other forums where I was more active and personally enjoyed more - HackForums and MPGH. I remember they had quite an active marketplace and sometimes the sellers would give out free alts.