how much can Askbot be customized, the code changed

how much can Askbot be customized, the code changed,

is there any license limitation that limits the extent how much the script can be customized for specific needs,

is there a way to get rid of the "Powered by Askbot" at the end of the page or this is obligatory to have this line at some visible place

Yes in the settings interface (user interface section) it is possible to customize the header and the footer.

Also, it is possible to create templates "custom_footer.html" and "custom_header.html" - all live in askbot/skins/default/templates - also it will be necessary to specify in the live settings that you want to hide the default footer.

Unfortunately, the skin is not yet finalized - so it is best to edit the default and ideally - keep it in your own git repository - because it really simplifies merging the code.

All of the code can be freely modified - git will help a lot to maintain your changes and upgrade the main code.