Yeah, when nothing blocks me from actually working the way I want, then things actually seem to happen. ^^
A new demo will probably not be coming any time soon, a lot of changes are planned for the "demo parts" of the game, so many that I will probably be forced to come up with a new type of demo as otherwise it will likely be too long. (it's already a bit long)
As for the physics, yeah, they will likely change even more in the future after a bunch of planned reworks have happened. ;)