Yeah I think a lot of what you said is pretty much how the people who disliked Nicole felt about the situation. Problem with her suggesting the idea when she's visiting Sunshine Bay is that it's so late in the game the MC would've been the one being shown in a bad light since he'd be still in a relationship with her but cheating on her with multiple women.To my knowledge no, only after the backlash they said that this was planed as a cuckqueen path, so no sharing, ntr etc. IIRC one of the dev's also got a bit hot headed in this thread, which lead to even more confusion/backlash...
Well back then there were no signs that she would be fine with just watching the MC, iirc as the MC asked her about a threesome her answear was, her with two men.
Yeah that advice from Gorgina was just crap imo, also to my knowledge of DMD (which is is dated) Gorgina was not in a open relation, but in a poly relation with the MC and his daughter, which is something different.
There where also many (including myself) who thought of Nicole just as a blocker, not a real LI and that the break up will be granted, add to that she wasn't exactly portrait in a good light...so many were rather upset about having no choice to break things up, being forced to be either Nicole only path or open relation was a bit like a slap in the face.
Overal i think the cuckqueen path with Nicole was not a bad idea, but not good implemented and at the wrong time.
The relation beetwen her and MC was already bad/strained.
They were on a break (which can mean many things) and in different countries .
Than how her sister and that client of her's braught that idea up, like a solution for solving relationship problems.
The whole thing is suggested by a call, with a rule that they wont talk about if anything happens (kind of a bad approach as trust and being open should be mandatory if that should work).
Lastly u had no real choice to decline it (only yes and only Nicole path).
Now if u had waited a bit, like now when Nicole is visiting Sunshine Bay, that could have worked much better.
Have her talk with MC, so their relation is at a better starting point.
Maybe have her getting aroused as she keeps seeing MC with other girls and she imagine him with them.
Make it her own idea, as she keeps getting off from imagine MC with the other girls.
Have a open talk with the MC about her idea and the choice for the player to decide.
That would have worked much better and if the players are seeing that her fantasys are about the MC with other girls, the whole thing would have been much better received , of course thats just my opinion.
If they had swapped the order of things in the story like her visiting/working in Sunshine Bay at S1EX, whenever she was calling to go open or breakup, and she cme to the idea of her being aroused by the MC being with other girls on her own without outside interference I think her path of being a cuckqean probably could've been implemented without much fuss.
As you said it was just so impersonal to suggest such a radical change in relationships over the phone and to do it out of nowhere with not much thought put into it. She could've even moved to work in Sunshine Bay at the start of the game when the MC got layed off and throughout the beginning of the game to the "Open or Break-up" choice she'd see the MC being genuinely friendly with all these girls and she'd fantasize about him fucking them, making her decision come more naturally.