1) The main difference between these licence types is that the Professional Edition licence includes the .psd files, and the Small Business Edition does not. You can see side-by-side product comparison on the
JobRoller features page.
2) Yes, updates are free
3) Yes, you are free to customize the theme as you like.
4) Yes, you can set these up as you wish.
5) We don't have a specific schedule for the frequency of
releases, but we do encourage community feedback and input in terms of
features you would like to see implemented, to give our development team an idea of what will be included in future releases.