Generate a big level from multiple levels

Hello.

I want to randomly generate a big level (one big closed complex of rooms and corridors) from smaller levels (rooms, corridors). I want every room to be developed as a separate level file. Question is:

  1. How to spawn a level in a location != vec3(0,0,0)?
  2. How to get an actor position in the level being loaded before it spawns? I need to get the position of an anchor (for example the location of a door) to understand how and where I can place this level.
  3. How to preserve the baked lightning?
  4. How can ‘level streaming’ help?

Any info or ideas is appriciated. Blueprints or C++.