Ness and Lucas don't learn PK Fire, PK Ice, or PK Thunder you know. In the description for Paula's trophy it said she taught Ness those moves before he went to Smash. Same can be assumed for Lucas.Robin uses Nosferatu too, so their is no problem.
Side Special PK Beam. In Mother 1, Ana could learn PK Beam, so technically Ninten could use it.
He also has access to teleportation and 4th-D slip, which the latter is basically another teleport.
Down special could be PSI Magnet or PK Shield (reflector).
To be honest, Mother 2/EarthBound is my least favorite, I've played through some, but I basically know the ending, it's the most generic kill the villain who wants to destroy the world.
Mother 3 is about family and watching the main character grow up.
Mother 1 is gives you Giygas's backstory and the origin of PSI, the whole deal with Magicant is much more interesting than EarthBound imo.
Itoi even said that Mother 1 was made the players, Mother 2 was for money, Mother 3 was both.
I have nothing against Mother 3.