Why should the Skull Merchant NOT receive a rework?
Revealing cosmetics aside (the only thing people like about her), she has got to be the most annoying killer to face in solo queue. She has Freddy's absurd lunge, killers always run Save The Best For Last on her making the perk seem overpowered (as well as Sloppy Butcher), she shuts down any loop which forces M1s every single time with just a flick of her wrist, she is a 4.6 m/s killer which ranks her among the fastest, she can protect any three gen formation with her stupid ability, the nature of her ability cannot be balanced, she doesn't need to mindgame to get hits, she has a terrible mori that is a Freddy knock-off (absolutely ZERO creativity), her Freddy knock-off claws are an absolute joke of a design, she wears a goofy bedazzled mask that provides her absolutely zero practical use, she looks like a survivor cosplaying a killer, her eyes look like Trickster's eyes, etc.
@DragonMasterDarren summed up her terrible design perfectly.
If I missed anything, since this was all off the top of my head, please leave a comment and I'll be sure to add to the extensive list.

Comments
I love going against two in a row...
Honestly I think she'd be fine if she couldn't reactivate her drones at will from a distance so you can actually get rid of them. Give it a like 15s cooldown and also let you start hacking them immediately instead of staring at them for 10s before you can do anything.
I think the rest of your post is mostly silly though. The obligatory "solo bad" whining. Ugh.
What about when she uses drones during chase to force an M1 by closing the loop instead of a full down due to the exposed status effect? I don't think that's very fair on maps where loops are further apart and you can't just move on to the next loop like you can with Artist and Trapper when they place their ability..
So she has some chance in chase as M1 killer only?
What exactly is your issue? Killer can use their power to injure me. Oh no, so broken.
Most killers in the game have way to injure you in loops.
I am really confused by title and content of this post.
I am currently Prestige 12 with her and keep going. So currently one of my most played killers.
So summary by me:
-base skin sucks (she looks like plumber)
But her new skins are great, I have created 3 good sets.
-mori is terrible, nothing to excuse that, it's just bad.
-STBFL and Sloppy are not terrible as for any M1 killer, but there are better builds.
I am switching between 3 builds, but only one is using STBFL and I consider it weakest, but fun to play.
None has sloppy, it's not bad perk for 3-gen, but there are better perks for it.
The statement she don't need to mind game for hits is incorrect. She is still M1 killer, she gets free hit only when you get trapped in corner of the map.
But you act like only she can do it. Most killers can get hit by using their power.
Once you get injured her power is reduced to movement speed bonus and information.
She has kinda Legion issue here.
I am not going to bother with talking about possible changes (issues with those) and what I would do. I have done that enough.
Personally, I have grown a bit fonder of SM since her mid patch buffs, especially with a chasing build where you just zoom around the map at 120% basically constantly, but if there is one thing about her that I will never budge on is that her base outfit is an absolute joke, I think it was made to be mismatched and crap on purpose to encourage people to buy skins, and I'm even more certain of that fact because her outfits have a ton of different good-looking combinations
It's a bit of a shame too, because Singularity exists and basically blows SM out of the water in every single possible way
You don't need to be in the corner of the map, take RPD for example. There's a strong loop in the main lobby but she can completely counter it with the drone and get a free hit because you cannot get to another loop - they are too far apart. With STBFL you can easily get that hit and before the survivor gets to a new loop they are downed. So she does not need to mindgame as I said.
Most killers can get hits with their ability but it takes time to set up the ability (Hag, Trapper, Artist, etc). Her ability just takes a flick of the wrist to shut down an entire loop and she can still move whilst setting it up.
Trickster, Huntress, Pyramid head, Deathslinger, Knight, Doctor and probably some more but this is enough to prove my point.
They also don't need to setup anything and they will destroy you on that RPD main hall loop.
This is not unique to her. Why did you act like it's most broken thing in the world, when there is multiple killers that can achieve same result or better?
And it's shocking, but killers don't spawn with 8 stacks STBFL.
You can predict Pyramid Head's ability on any loop, Trickster can't use his ability efficiently on loops with high obstacles/clutter, Huntress can't throw a hatchet though a high obstacle/clutter and is easily predictable, Deathslinger cannot shoot through clutter and over high obstacles and is also predictable, and Knight is a different story. Her drones work through any clutter and high obstacles. Even two stacks is enough to have a significant impact on one of the fastest killers in the game.
You are dead on that RPD loop in main hall against Huntress or Trickster. You wanted to use that loop as an example.
You can't predict PH if he knows how to flick.
You can't predict Huntress if she knows how to flick.
Her drones have an area effect, unless your back is against the wall, you can just hold W away and she can't do anything to stop you.
So what she can injure you when you get into corner? You are still not dead and she is M1 killer.
Legion can easily injure anyone anywhere and they are not considered strong killer. It's nice to injure, but it doesn't mean anything when you can't down fast enough.