From what I understand, in EFU a character's stealth can vary from their base score plus stats and items if the area they are in is darker or lighter than the norm. My questions are thus:

Does each area have a set modifier, or are the modifiers locational yet again within a single area?

and;

Do items that provide an ambient light effect, such as "Green light 5m" or the Light spell, adjust a character's stealth also?

9lives Does each area have a set modifier, or are the modifiers locational yet again within a single area?

9lives Do items that provide an ambient light effect, such as "Green light 5m" or the Light spell, adjust a character's stealth also?

Every area has it's own modifiers. And not that it matters too much, but just for information, the modifiers are actually applied to spot and listen checks, not to hide and move silent.

Items that provide light have a couple modifiers. They give you a bonus to yours spot and a penalty to your hide.