Spy Camera locations:Base Game:Girls' Locker RoomGirls' BathroomSports AreaPrincipal's Office (requirement for Hardman chain)Upgraded Computer RoomGym Storage Room (requires Titsbig chain to start)Added By Lexville:Swimming PoolRoofProbably the basement; not sure of thisAs for triggers, I just don't know. As far I know no timing on availability has been changed. I've had the Girls' Locker Room spycam trigger event happen in the first two weeks but also significantly later. Same with the bathroom and the Sports Area. They usually only fire when there's only one girl in there and it's randomly chosen as to whom. Though I am enjoying the Base Game right now, I'm eagerly awaiting 1.10 to go public so alkalash can update for that - when he finds the time/drive to do so.
The Cheerleaders Club shouldn't matter. If I recall correctly, so long as you have either the Kendo Club, Swim Club or Cheerleaders' Club enabled, the trigger point should be hit eventually as all three of those clubs use the same changing rooms.And the Basement camera, as alkalash said, is part of the base game. A Library camera was added by Lexville.