Here's my theory:
-If you lose the Eye, you miss out on some lore and or Corruption and maybe some Power.
-IF you pick Aglaecwif you get an unlocked side route like when we visit the girls; but it'll only be available to those that picked her. Bout the same way Demi route isn't available after you kill her. The side route will maybe provide Corruption, Power, some sex scenes, etc.
-I think regardless if you picked Aglaecwif or didn't; by the end of the previous mentioned route, it'll betray you and try to kill you. This would make it so that even if Deryl is the one to do the deed, both of you have to take down this spawn eventually so the game doesn't branch out too far. The pay off is the aforementioned additional route points.
-IF you save Laurie there may be a potential threesome? Not that that fucker Deryl deserves it, but still; maybe it'll be an option? It could also play out where she may help us for a future fight as a way of perhaps stopping a skill check or something down the line, about the same way Brianna saves us from Valravn if you aren't strong enough; you can miss it, but it's there.
-I don't think the questions you ask Aglaecwif will have any impact, they SHOULDN'T as you can't even ask all of them and if you ask even ONE you're missing out on power or skill, which we ALL know is vital for fight checks down the line, training be damned.
One thing is for sure; this game based on this latest choice has branched out BIG time already. And unless I get a next update info drop on what does or doesn't happen immediately gonna have an aneurysm.