here i am spouting my Opinions again
No, absolutely not. It has the speed, coverage, and now the typing to pretty much trap any and all Steel-types in the game. Over at Megas For All we've already hashed this concept out during the Electivire slate and realized just how unhealthy and fundamentally constraining such an optimized trapper would be. Due to the effective range of its trapping abilities, it would be legitimately comparable to auto-trappers like Dugtrio, which can utilize a potent STAB to instantly invalidate and remove anything physically frail or weak to it. Considering this Electivire would have the typing and coverage to make what's, otherwise, a borderline ability that's standardly balanced by a user with limited options work to its best effect, and consequently invalidate an entire chunk of the metagame a la Dugtrio, I see absolutely nothing positive coming of this and I massively discourage exploring this concept further.
This would honestly be a pretty substantial change despite its simplicity since this new Speed tier would allow it to actually 1v1 a lot of the offensive metagame it couldn't originally, but considering it does genuinely address Obstagoon's core problem as a wallbreaker I think it would be certainly fine to have and is probably the change I like the most in this slate. It's not quite enough Speed to be difficult to revenge kill, but it's enough to give it more practical application against bulky offense builds. It would also most definitely still be balanced by its incredible proneness to residual damage via Burn, hazards, and contact effects. Furthermore, it boasts a U-turn weakness and is reliant on Facade to actually consistently sting. This is certainly fine, if anything I worry it won't do enough for it, but I think having another viable offensive Dark-type is always welcome in a metagame where viable Ghost-resists are brutally sparse.
Okay, I suppose. My main nitpick with this is more that you really missed out on the opportunity to use Early Bird, but this is certainly fine considering just how substantial power creep has become since its inception to where I think it'll probably be balanced. I believe it would be really debilitated by residual damage, especially if it wants to make use of Head Smash, and it looks like it would hate dealing with Ferrothorn-centric cores in general which are incredibly potent in the current SS OU metagame. I'm not particularly passionate about this because I don't think it necessarily adds a lot to the metagame, but it seems harmless enough.
So this would essentially just make Jolteon a much faster Heliolisk? I suppose it would help since fast Electric-type pivots are so blanked by Ground-types, and giving one with an incredible Speed tier the option to pressure Ground-types directly seems like a pragmatic choice. This being said, I don't exactly feel this will be enough to make it worth using over Tapu Koko and Zeraora, the former of which has a secondary STAB to blast Garchomp, and the latter being probably the best natural late-game cleaner in the metagame next to Dragapult. In terms of the fast Electric-type pivot with an option to play around Ground-types directly, Jolteon is still heavily blanked by Grass-types and Ferrothorn to a point where I just do not see why you would use it over Tapu Koko in particular, even with Surf. Scald Raikou also exists, whose viability is already in question.
edit: lol nevermind raikou got buffed, raikou actually just overshadows this a million times over
Shore Up would probably make this thing an absolute juggernaut and probably
the Ground-type of choice on bulkier structures. The comparisons to Hippowdon are fairly apt and would be ones I agree with for the most part, since on the Special side it roughly simulates Hippowdon's bulk (letting it check Dragapult and Heatran), and Stamina lets it accumulate bulk to a point where it could also start doing things like check Melmetal and Victini. Furthermore, Stamina could give it winning ability with Body Press and the ability to attain some comical feats, such as 1v1ing things like Weavile if it accumulates Stamina boosts beforehand. In fact, being a Ground-type with the ability to actually 1v1 Ferrothorn and Corviknight with Body Press feels incredibly fascinating and practical, and probably the most interesting reason to use it as a Ground-type. I'm not sure if it would be too worrisome of a change, but I can safely say Shore Up would propel this thing into top status considering how much it could consistently check with its incredible natural bulk and the potential to check with Stamina. I don't know if I directly support this per se, but I guess I'd be interested to see how it'd pan out. I will say, though, that I really don't see the point in +10 Defense; such a buff feels unnecessary and overtunes Mudsdale's defensive profile. If anything giving offenses a hole to exploit before it snowballs boosts feels like a much more dynamic balancing factor as a bulky Ground-type with longevity, so I feel I would support omitting the Defense boost if it gets Shore up.