You basically posted 1 bug and 1 thing that you didnt seem 'to get'.
The bug you listed was the hooker going invisible/disappearing -this is most definitely not a base game thing as the base game has only 1 special character to be hired for marketing which is your old school mate - so i am almost certain you are dealing with a mod problem and as such your problem doesnt belong here.
Using a condom has nothing to do with birth control or not - the relationship between you and the opposite is what triggers those request combined with traits. Some dont like cheating etc thus they will always insist on the condoms.
To finalize my comment from earlier: It is common courtesy to take responsibility for things you break and fix them. No doubt about that. I personally am both a modder and dev and as such i started to get really annoyed by the constant bad-mouthing of Vren in this thread by especially those that claim to provide 'fixed' versions of the game with their mods. Most of the base problems disappear once the patreon test is done - all the latest major stuff was not even in the base game but caused by conflicts created by the mods.
So you know for a fact that when the mod converts a hooker into an "employee", that employee isn't being handled by the game anymore?
Are you saying that the employee is handled by the mod? As in the game doesn't have an employee system?
Are you almost certain? Would you like to phone a friend?