Questions About Specific Sims in the Manage Households Tab

*I did ask this question on The Sims 4 Forum, but I figured I would ask it here, too, because I am looking for as much feedback as possible since my web searches have turned up conflicting answers.

I am starting to build a "Custom Save File" for myself, and I have a few questions about specific Sims in the Manage Households tab.

I have moved the regular townies (the Goths, the Landgraabs, etc.) to the My Households tab by "favoriting" them by clicking the heart, and I will be marking them as played, as I plan to play all of them in rotation.

However, I have some questions about specific special townies and NPCs from certain Expansion/Game packs. As I mentioned above, I have searched for the answers to these questions prior to writing this post, but I have found conflicting answers so I am still unsure so I figured I would try asking here.

Concerning the Henford-on-Bagley NPCs (like Kim Goldbloom, Michael Bell, etc.):

I want to protect them from culling/being randomly assigned other roles by the game, like bartender, food stall employee, etc., but I don't want to mark them as played, as I understand that will make them lose their special NPC roles (as grocery cart owner, creature keeper, etc.) If I favorite them by clicking the heart icon and move them to My Households, but don't actively play as them, will this achieve my goal of protecting them from culling/having them keep their NPC roles?

Also, can I edit them in CAS through the Manage Households tab (if, say, I wanted to change their outfits) or would that cause them to lose their NPC role? I have searched for the answer to this question, and some people say editing them in CAS will make them lose their roles, while others say it would be fine, so I am unsure which is correct.

Based on the answer I received to a previous question a few months back, I understand that, as far as the Scott Family is concerned, I can evict Sara and her husband from their home if I want to use the home for my own Sims, and as long as I do not entire live mode with them and mark them as played, then Sara should retain her role as Pub owner. But can I edit her and her husband in CAS, or will that make them lose their special role?

Also, from what I understand, HoB families like the Watsons can be edited freely as they are more "townies" then NPCs involved in the HoB errand system, correct?

Concerning the Realm of Magic Sages:

I understand the game technically considers them unemployed, so I want to prevent them from losing their unique role as Sages and prevent them from being randomly assigned odd jobs by the game like bartender, food stall employee, etc. Is it safe to move them to the My Households tab by clicking the heart? If I do this, but avoid playing them in live mode and marking them as played, will they retain their roles? Also, can I edit the Realm of Magic Sages in CAS without making them lose their role, or no? I have also searched for this answer, and some people say it is fine to edit them in CAS, while others say it will make them lose their special NPC roles, so again, I am unsure.

Concerning Island Living Mermaids:

Same question concerning the IL mermiads that come with the game - if I move them to the My Households tab, will they lose their role as NPC mermaids, and will new mermaids spawn in their place? Or is it safe to move them to the My Households tab? Also, I read somewhere that they cannot be edited in CAS - is this true, or can I edit them freely?

Concerning Discover University Professors:

Basically the same questions as above: Can I move them to the My Households tab and edit them in CAS, or will doing both/either of these things cause them to lose their role as Uni Professors?

Concerning Father Winter:

Finally, in the case of the original Father Winter, Clement Frost, from what I understand he is immortal, but I want to protect him from being assigned a random job like food stall employee or whatever (I would consider that very immersion-breaking!) so can I favorite him and move him to the My Households tab, and can I edit him in CAS, or would either or both of those actions cause him to lose his special role as Father Winter?

If you've taken the time to read this, thank you so much, I really appreciate it! I know folks here are really knowledgeable about the game, so any answers you can provide to these questions based on your experiences with households in the Manage Households tab would be very helpful.

-AalyahReed

(P.S. In case it is relevant, I do not use the Neighborhood Stories feature, but I will be using MCCC.)