They have never provided proof of their mining centers despite multiple claims that they 'soon' would be. I don't think that there is a mining center. I think that it is a Ponzi!
sorry for the dumb question, but it's because I do not know !! What is a Ponzi?
multibit doesn't require to download the whole of the blockchain and can be used as a offline wallet I think bt armory and bitcoin core are the ones to go with if you want a secure offline storage.
I have followed the TOP 20 I was struck by the same values (also the account number) and, if anyone has the curiosity and take a look, you'll notice something amazing !!
It means that the whole TOP20 is faked? i think it isn't even random generated.