Bau my friend, you have not left xat
Block ip trolls -- I do believe this is being worked on in some way shape or form. There have been some restrictions added for bots and spammy things, but its a bit hard to expand this to users because of VPNs like previously mentioned
Do not allow the same person to register under a different name, fake name -- This would help, but again, VPNs
reimburse each user with 100 xats every week (A way to attract new users)- This would raise the cost of all the things on xat... economics.
when a chat owner is reported, consider convincing evidence why a person reported it. Because i have not seen until now that an administrator in the chat is reprimanded for the bans or abuses that he/she does with the users. -- When chats are reported, they run risk of being delisted from being promoted on the chat. For this to happen though, a TOS violation would have to occur. These types of things you wouldn't necessarily see, but doesn't mean nothing is happening.
Promote xat on google -- I think xat is listed on Google, perhaps other means of promotion though could be looked into