You gotta be careful with this one. Doing this may mean trolls will post nasty comments in the review section, where the uploader cannot move them. Allowing the uploader to remove/move reviews, however, allows them to delete all the ones they dont like.
for this reason, you should probably leave the moving to comments to the moderators, with a "report to mod" button.
Forgive me if this comes off as rude, since it isn't intended as such, but didn't you basically repeat what I said?
Reporting the comment to a moderator is what I meant when I said "requesting deletion or moving".
Something that could be used to prevent trolls could be a VIP system. I system where comments made by new or untrusted users can be deleted by the uploader of a level if he is a VIP member. Likewise, VIP member's comments cannot be deleted by uploaders, only moderators. This way, the known and trusted members of the community have the ability to defend their levels against spammers, and since known members are highly unlikely to make spam comments, a mod would have to review it to clarify it is indeed, trash. Of course an untrusted user could always report the unfair removal, and if true to their word would be replaced.
Of course it has flaws, but nothing proper planning could not take care of.
Just an idea though. Take it or leave it.