What do you mean ? It should look as dark or as bright as you want. Regardless of how many lights you have in the room. You have post processing settings where you can easily adjust the exposure from complete darkness to one million.
Regardless Lumen vs baked, Lumen should be only if you have certain dynamic things happening which should influence the GI/lighting of the environment. But in this kind of game everything should be baked, in which case the performance should be very good. And with baking you should be able to place as many lights as you want without any penalty.
The glare thing should be also adjustable from post process.