1.Stats: Should Sudowoodo get a stat boost, Evolution, Mega Evolution or nothing?
Sudowoodo is, for all intents and purposes, terrible. Its BST is reminiscent of a middle stage Pokémon, its abilities are hilariously generic, and its movepool is simply not strong enough, despite its versatility.
As a version counterpart to Mr. Mime, Sudowoodo can get a proportional stat increase to around 440 BST, which would be around +30 more stats. However, this too would keep Sudowoodo terrible.
An evolution makes the most sense, given Sudowoodo's stats. However, cross-generational evolutions will likely not come back, and Sudowoodo is already tall as it is.
A Mega cannot work without any stat boost first.
2.Should Sudowoodo get more abilities?
Sudowoodo already has three abilities, so new ones are unlikely. Best ones would be Sand-based abilities, Reckless, Iron Fist, Contrary, Arena Trap, Aftermath and Shed Skin.
A Grass-type equivalent of Steelworker would be fantastic as well.
3. Should Sudowoodo get more moves?
Sudowoodo already has a nice movepool. Superpower and Close Combat would make the most sense. Accelerock would be good. Other moves like Assurance, Beat Up, Encore, Focus Energy, Follow Me and Rock Wrecker would be good, so would Wide Guard and Punishment. Iron Head and Zen Headbutt would be cool as well.
Though thematically making sense, Sudowoodo is too light for Heavy Slam. Bonsly would like it for Little Cup though. Bonsly can also get some moves exclusive to Sudowoodo like Hammer Arm and Head Smash.
4.What additional typing Sudowoodo can have?
Grass and Dark are the most obvious ones. Fighting and Ground are the lesser obvious ones.