Efficiently lighting large areas and tight corridors

I’m building a map and I’m struggling with getting it lit well. The map consists of a large arena (50m radius) with 2 floors of corridors below it. I’m struggling to light this nicely. All attempts either turn out too dark, too bright or all the lights start overlapping and I start getting shadows being cast through walls.
The Map
The arena
The corridors

Lighting attempt number 1
The lower round room in the corridors. Too Dark.
The arena, with wall selected so you can see how far the light falls short.

Lighting attempt number 2: corridor light’s attenuation radius reset to default, arena’s increased even more.
The engine’s complaints about this state of affairs.
The Arena
The round room (I just realized the lights in here are too close together…)
A Shadowy Problem. I’m pretty certain this shadow is being cast from the light in the corridor below. If I could fix this problem I’d be ok with the performance loss, which I haven’t really noticed TBH. I’ve been bashing my head against this problem for the best part of a day now and while there’s tutorials introducing you to lights and such, there’s little about actually effectively lighting a level.

I’m a noob, so take my suggestions with a grain of salt. But, I would like to give back where I can. Try changing your point lights from ‘stationary’ to ‘static’ (in the details pane). This will get rid of the red x’s and allow you to place more point lights without them being too close.

With that many lights it might be indeed wiser to use static lights. Make sure you have set up your lightmap UVs correctly.