Server error launching Google Play store
When I randomly get server errors from Google Play, I usually resolve by removing /etc/hosts file (a rooted phone and an ap like Root Explorer is needed). Sometimes I have to reboot the phone, sometimes it works straight away.

Tip: To be sure avoiding system breaks and soft bricks (for how unlikely it is doing this operation), instead of removing the file rename it to something else, so that you can restore it back if needed.