It appears that comments to posts in this comm are restricted to members at present. The interim mods, myself and nox_candida, can't change that. We can approve requests for membership, once we check that the LJ account isn't a spammer.
I'm sorry, we weren't aware of this default setting.
After the authors' names are revealed, remixes should be available elsewhere, including AO3 in the Sherlock Remix community.
On Wednesday, innie_darling, the comm maintainer, will be back. She's put a tremendous amount of thoughtful work into this challenge from the beginning, and we thank her for it.