So this was very round about, but it seems the only way to force Richter to change Marazet while not bothering with Gethra and/or Elami, was to do a very specific series of events:
1. Win against Akarion but don't TG him. First Mingle Phase doesn't matter much, since you need to lose to Tessa during challenge 2.
2. After loosing to Tessa in Challenge 2, resisting her maid training, and making sure Richter isn't TG'd and MC'd by Rhianna, make Reese undergo his Maid TF while making sure he's subservient to Maid Lois. (Reese's location is in the garden, so you have to save Richter through event first, then do Reese's Maid TF)
3. After sabotaging Tessa in Challenge 3, ally with Richter during mingle phase 3, so that he gives Lois Influence. Make Tessa into a Barmaid, then afterwards, seize all influence from both Reese & Tessa.
4. TG Odenval during Mingle Phase 3, then proceed through Challenge 4. Marazat actually losses out to Base Rhianna so you should not TF Rhianna at all during Mingle Phase 3.
When this is all done correctly, doing the Golden Light Tavern event this way is the only way to ensure Richter turns Marazat into a barmaid personally. So if the bug with Marazat has not been fixed for anyone whose reading this, this series of events is the only way to get Barmaid Marazat currently.
There are actually several steps to follow beforehand, you don't need TG Odenval, you just have to talk to Richter about Rhianna's Raising and to select the second option and then ask for her hand, Richter will ask us for 5 influence and after the court go to the tavern and after a while he will give us the option to give Richter all the influence and he will transform Marazet.