These are 3 Scenarios I can totally see happening with Cindy and I assume Axel is the obvious other Option if Ian doesn't progress the Cindy Story after what happened in Chapter 7. And it's great that you mentioned the Importance of just kissing Cindy or fucking her in Chapter 7 because I also think this is really important for the future of her Route.
I just can't think of any way where Ian and his inner Circle could survive an IanxCindy Path where they actually get together and fall in Love (unless it is at the very end of the Game). So I think IanxCindy is like LenaxJeremy on the other Side the one Route where I can see soo much drama and destruction for Ian and Lena if everybody get's to know what happened.
I think that's where some of the difference between "romance" and "sexual" paths could come into play. Regardless of what the player chooses, Cindy will remain with Wade for a while. If you have chosen to help them mend things, then they will probably have, although I think it would be more interesting if it was more difficult than that and Lena had to play a role too.
For those that went in the alley with Cindy the path could progress mostly the same but with a confrontation taking place at some point about what transpired between them. If they went all the way and had sex they would also have been caught by Ivy and Jeremy, perhaps that path could be more about giving in to the pleasure and rutting like teenagers?
If you kissed her or didn't progress past that you have opened the relationship up but without going all the way. I could see this path as being one of more restraint, where you have to deny the temptation of doing the most attractive character in the game continuously to unlock her romantic content.
Regardless of the specific of those two routes eventually Cindy and Wade will break up.
If you fucked Cindy early then this becomes public knowledge and will influence the friend group. I have a hard time seeing Perry be okay with it.
If you kept your restraint then Cindy becomes single and Ian may be able to romance her normally. Now, obviously she would still be his pal's ex and that is bound to make things awkward but if you've done things "by the book" perhaps Perry will not be hostile.
On other paths Cindy might just leave the friendship group, if she doesn't stay with Wade. Maybe she opens up sexually. Perhaps this happens with both Axel and the path where Ian doesn't even kiss her? I'm unsure about how that last one might play out.
It seems given that the Axel path would lead to a "free Cindy" outcome where she chases the modelling dream and starts fucking around.
I'd love to see her as a part of the SlutLena/Ivy/CorruptedHolly entourage.