I believe Zscript needs to be dropped, all THAT has done was open the door to jillions of bugs! I'd be more then happy for you guys to restart from scratch, just make sure you do your research before choosing a new system to base it on (SDL, Allegro etc.) and choose one that best fits your needs!
Freedom's analogy is somewhat perfect in my eyes. fix the big bugs now! (excluding zscript which is currently in a evil incarnation!) and release a version then work on a new one from the ground up!