What I am looking for is simple in concept. I am looking for a mod that adds a dialogue option for any NPCs that own houses that lets the player choose to buy the home from the NPC and make the NPC house the new player home. It doesn't need to have Hearthfire features, it would be a good mod if all it did was set the house and everything in it to be owned by the player, give the player a key to the house, and kick the current npc out. Although since these NPC houses are often just named something like "Faendal's House" an option to rename the house would also be apprecaited.
I'm very new to modding, so although this sounds easy on paper, I am not exactly sure how difficult such a mod would be to create. I'm not sure how easy it is to toggle ownership and trespassing, might require some big scripts. I'm really looking for 3 things, ideally this mod already exists and someone can tell me where to download it, secondly, someone with modding experience really likes this idea and implements it well into the game, or lastly I try a choppy buggy attempt at the mod myself. If I do ever attempt the mod myself, I'd still like to know from more experienced modders what I should be expecting in terms of challenges and what the general route a modder should take to implement such a mod without causing big conflicts.
I also have a couple secondary ideas for this mod as additional features. One feature that might be nice is a rent / roommate feature that lets the player live in the house at a cheaper price, but the player has to live with the previous NPC owners. It would also be cool if there was a house selling feature where using persuasion the player could sell houses, or perhaps even give the house away for free to the homeless. I think it could be a really neat mod for immersion that gives the player more to do with late-game money and also a lot more freedom.