Yeah, and some Ground types are hurt by Electric attacks.
well, that's easily explainable. I mean, ground types have a certain limit to their immunity to electricity, but if the electric pokemon uses an electric attack that is so powerful with a concentrated dose, that it actually is beyond the limit of the immunity, and thus is affected by it in the same manner as a pokemon not immune to electricity (or any type for that matter).
If you want a good example of this, In the Final battle against Bowser, Giant Bowser used the Star Rod to become invulnerable, and to add insult to injury, the Star spirits original beam attack, the Star Beam, is made uneffective against him at ALL.
BUT! when the Star Spirits regain most of their power via Peach and Twink, not to mention the rest of the Mushroom Planet, they upgrade their original Star Beam to the Star Beam MK II, AKA the Peach Beam, and the attack has become so powerful that Bowser's newfound immunity to the attack no longer exists.
It's a total shame that the Games seem to ignore this, I mean, they could have implemented the entire thing into this (By that, I mean the Hand held Items that make a pokemon more susceptible to a certain attack don't count.)
As for swift/aerial ace being unavoidable, the only reason it was unavoidable in the games is because in the games, the pokemon battling each other were sitting ducks. Believe me, if the games had them actually moving around (Like custom Robo), Swift would be just as unavoidable as the anime (meaning, it won't be unavoidable). Even In Battle Revolution, they were still for the most part, Sitting ducks (Since, you know, they don't actually dodge.).
Also, the Arbok evolving into Seviper thing was dub only. Actually, the segment that dealt with it, "Trainer's Choice" wasn't even PRESENT in the japanese version.