1.) lod on geo is very important (at least for me) when modeling cities or huge landscapes. I create 3 lod stages of the buildings:
a) full model and interior of the building
b) just the outside shape of it (no interior at all)
c) a very low poly version of the building (very small textures)

the code will replace all stuff when needed and so you can make huge levels with indoor (watch out for not wasting to much memory...it needs to be reloaded!!!).

I know the engine clips away everything not seen all alone....but this way you have way more control of it and the engine doesnt need to bother if to clip or not.

Works like a charm for GTA like levels...for shoters it dont make much sense..or at least not very often.

2.) lightning is a little bit bahoo with the engine so far...i would recommend replacing a flare (either with an afterglow shader or a simple sprite) at the position of the light once you get far away.

check the halo() function for that...just make sure to fade out at a near and far distance to the sprite.

..should work