I can answer 3 and 4:
- If your game needs the levels to be built on-the-fly and at runtime, then you need to go with dynamic lighting (GPU intensive, worse the more lights you need, not as bad if you just need one sunlight / directional light), or make everything unlit (fast but you get no shadows, etc).
If your game will work with levels built ahead of time, then you build a dungeon in a level and can Build Lighting to bake lightmaps for that level, just as if you built the level by hand and used static lighting. Most VR games use baked static lighting for level geometry, so do that if you can!
In my game, I want dynamic randomized levels so I’m using dynamic lighting, but it all takes place outdoors so I only need a single light source.
- Yes, works fine with forward renderer.