If you have purchased Dark Basic Pro then you have the license already to produce and sell your own software. However, if you end up using other plugins/media that did not come with Dark Basic Pro then might find that you either need permission or purchase a license for those too. All these you can add to your own EULA.
Yes, you can publish your own stuff to your own site so long as it 'not' in a commercial manner unless you have purchased the Dark Basic Pro license. All media that comes from another source that is included in those projects you may need permission for though.
I hope this helps a little...
Mental arithmetic? Me? (That's for computers) I can't subtract a fart from a plate of beans!
Warning! May contain Nuts!