Wow... Playmofire, this is an impressive piece of work.
I disagree that the only occasion to use other than 90 degrees is for outer walls. There would be several especially big buildings for that this would be interesting... But something like this (especially for the floor pieces) is quite difficult to design on the scratch, I think.
I like your steck system. But what is the benifit to the old steck system? The two sizes we also have in the old system. You are substituting the connectors basically, but how do you realize a T-connection? I need a connector there but then two pieces with a T-connector would be wider than the big piece, wouldn't they?
I would love to see prototypes of your system, especially your idea with the floor connectors is intriguing as you would really get a smooth high wall without any transitions. Would probably look pretty cool for castles...
Your new pieces are great. Thanks for your effort here.
best,
socrates