Hey.
I'm here to reply about the rain. This was explained already, but I'll post it here too for public. There are also official information about this on our Forum posted over a year ago, explaining how rain works.
All users can get rain, everyone has ability to receive it. We can't just restrict someone, as Edward said. Considering the fact the rain was implemented to award active chatters, it's normal that the main thing that will have effect on this is quality of their messages. Rainbot was designed to select few users randomly to get some free coins.   
Users that were spamming, thus abusing chat rules, will reduce their own chances of getting it. It works towards awarding the users that are respecting the rules. If you're muted, and were breaking them, it's normal that you won't get any award funds for that.
And of course, it is needed some luck to get picked, since the number of active chatters is increasing day by day, you can check that yourself.

I just have to point out again, that VIP star won't make you entitled to get rain. VIP users get lots of other kind of benefits and free coins. VIP and nonVIP accounts are same in this regard. I've already explained how the rain distribution would look like, if the main parameter for rain is how much someone wagered. Rain was added precisely to award all users that are actively chatting, no matter of their rank. You would just have to make an actual contribution to the chat and I assure you that will be recognized and awarded.