loftar wrote: I appreciated some of the points in the OP as things I might not have thought of if not pointed out.
Thanks for the appreciation. I am planning to keep updating the topic with the new ideas as well.
If anything, I would vastly prefer a system that requires as little formal UI (like a blueprint designer UI) as possible
That would be amazing. I already imagine people selling their blueprints at the markets and working as architects in hafen

but if it's a necessary evil for a greater end result I may be open to it.
TBH, the blueprints system you've noticed is a great solution. Especially if you could customize stuff on the forum, then craft the blueprint in-game.
1. What to do with door system (as you remember entering a house is a teleportation to another map)
2. Indoor mechanic need to be revamped (to the system of determination where indoor starts, and when outdoor starts)
3. Tons of bugs that will be come from 1. and 2. (for example, how to prevent opening a container through wall from outside?)
4. Other things of mechanic that invisible for players.
Blueprints could resolve the issue. Just do not use the houses as walls

and make sure that you've tested everything regarding house-jumps.