Thanks for feedback!

• If PIN code is wrong for some reason, after few attempts Surfer clears all credentials to save you from brute force attacks, of course you can relogin and set up new PIN after that.
• Glad you like that ;)
• We are working on theming and firstly night mode feature for next release and as we continue development we will add more options to tweaks
• 10% mostly goes for development team we have and servers we provide for the community, such as hosting your images for free, notifications, api servers, etc. And any additional is used for improvement of the services continiously and bringing new applications, services on top of Steem.