I don't need a horror manga about lolita; seeing anons talking about googling buyers' addresses and internet stalking the winners of LM auctions to find out their age/location is scary enough. Maybe google maps stalker-chan flying to her buyers' homes and breaking in to give herself a house tour but never stealing anything or hurting anyone and just creeping people out would make a cool horror plot though.
If I read a lolita comic it would be a cute girly shoujo/slice of life or looking for romance thing a la Aggrestuko, maybe about a Misako-esque person who loves wearing lolita and just really want to find a guy who doesn't mind it and isn't a creep and all the different scenarios or lolita friends or whatever could come from that. Heck, maybe at the end of one volume she realizes she is gay/bi and spends some time dating other women too only to find they are also judgemental if they don't wear the fashion. There's a lot that could be done with a basic premise like that and it could go on forever if it's something you want to constantly update.