Alraune

You can actually disable the sniper through Lenny's Simple Trainer. There is the option to disable it, but you'll probably have to turn on god mode when crossing through Blackwater because the bounty hunters there are really OP. Afterwards it's not much problem and you can go around New Austin You don't say! I've been using Neightive Trainer (which incidentally looks like it was updated yesterday, which I'll have to check out) but I'll have to give Lenny's a look too. Thanks so much for the tip!

You can use this save editor to change one of the horses you already have into a Gold Turkoman! (You cant add horses to empty stable slots, only edit horses you already have) (If you don't wanna feel like you're cheating, you can save up for the amount that you'd need to purchase the horse and then just remove that from your money total in the save editor when you go to swap out the horse type.) It looks like a simple "turn the New Austin invisible sniper off" mod is still a long ways off, at this rate, so this is how I've chosen to give my Arthur a tiger-striped bay mustang to go through the story with. It sucks having your favorite horse gated till after the epilogue. :[ This may work for guns too but I've not messed around with that since the only thing I needed this for was the horse.

So much interesting character development happens for Arthur explicitly because he's dying, though. You'd have to change a lot of dialogue or omit some scenes altogether if the goal is to skip the moment he contracts TB from Downes. It might be possible, but I think it'd be a significantly lesser product without something added to make up for what had to be thrown out. This seems more like an experiment or a proof of concept kind of thing than an actual alternative ending. Or, at best, the groundwork for what could someday be a true alternate story once our understanding of the game and modding tools has advanced enough.

I think the biggest hurdle here would be the creation of the new ending itself, and changing old missions/adding new ones so that leading up to the new ending actually makes sense. Even without voice acting, someone would have to animate all of that. Making entire new cutscenes, essentially, is as of yet unprecedented for this game. It's a very ambitious idea, but I don't think it's one that would happen for a long time.

Online-only content in singleplayer in general are ripe ideas for mods, I think (such as the horses). Would love to see more weapons in story mode

Hope the title isn't too spoilery. I would love to see a mod that basically replicates the glitches found in the on-disc version of the PS4 game (the ones that were sadly patched out) that break the bounty hunters/invisible snipers that prevent you from going to Blackwater or farther west as Arthur, before the epilogue. Don't really care if all the features would actually work (given that quests and stuff are for the most part probably not designed to interact with a character who normally isn't allowed into the area), I just wanna be able to explore there as Arthur for Arthur reasons. Given that these glitches already existed in the PS4 version of the game and were only patched out later I'm surprised they've not already been replicated, but I'm also unfamiliar with the modding scene of Rockstar games.

+1 would love to be able to get rid of excess guns

Even if both of us legally had copies of Oblivion and Skyrim it would be illegal? :/a I guess I hadn't thought of that but it kind of makes sense I suppose. Not everyone has both Oblivion and Skyrim. Ah, well, how would I start going about doing that?

This probably isn't possible, or terribly complex if it is, but something I'd really like to know how to do (or have done if someone is bored or feeling generous) is import the Oblivion Frost Atronach into Skyrim. I like to play as the same character I had in Oblivion, and she had a Frost Atronach familiar, and it's just off-putting that it looks so different even though in my head it's supposed to be the same Atronach. (right now I'm using a scaled-down Skyrim Atronach with a Nord voice) :[ I could probably figure out how to make a silent follower out of it after all the animation stuff is worked out, I just have no idea where to start for doing something like this. The extent of my modding knowledge is making basic followers in the creation kit and some modeling/porting I used to do with FFXI stuff. u_u Any advice would be appreciated.