Answers.
1. I have a porn site at .com and now I have one at .XXX. I've doubled my # of porn sites. This will happen at millions of sites.
2. If there are no .XXX sites, then fine it won't matter. But if this new domain is opened up for porn, then guess what. More porn will infiltrate the internet. Block it if you will, but will that detract some pervert who will view it, and then molest some child?
.XXX is a bad idea.
Nonsense. Two different names can, and often do, refer to one and the same site.