For floor plans, there is Bonsai as a Blender addon. It is usable and does a lot of what you want (and tons more), if needed you can also script it with Python or create its native IFC format through Python libraries:

https://extensions.blender.org/add-ons/bonsai/

FreeCAD can also do 2D sketches and you can snap to angles, enter target lengths and skript it in Python. But even though it is older than Bonsai, it is harder to use (imho) and less stable (save often).

And if it is strictly about relatively simple floorplans, try sweethome3d. Slowish because it's java, and cannot do a whole lot, but enough for quick sketches.