It's not Google.
For some people, that's not a good reason, but for me it is. The fact that it's super fast, very powerful, and are an Australian company (I live in Australia, so things are very fast) are merely bonuses :)
I'm pretty certain the Fastmail servers are in New York; so that's a bit of a funny reason ;-)
No. We'll look into it.
> 2. Can I move mails from spam to inbox and from inbox to Spam?
Yes, tap the message while open and use the "report spam" or "not spam" button (the shield icon).
(and ssh into the servers, bliss - even the VPN connected faster)