if its anything like what they say theyre planning, then all user data will be ported from your Wii U to the NX. meaning once you do that, your Wii U data is wiped clean and you can continue playing on the NX.

I'd say yes just do Super Mario Maker as it benefits the most from the user created content.

Super Mario Maker would be an absolute must if it ends up on NX.

MM yes because you'd like to maintain the existing community as much as possible. Smash and other online games like Splatoon should have their own original iterations on NX and should not be cross-platform with the Wii U.

Maybe.

TBH I don't see Nintendo allowing the two platforms to be cross online.

That would be especially true for Super Mario Maker.Maybe Smash can get away without this, but Mario Maker needs to start with all the content already created for the Wii U version.That way will make for a more awesome experience with all of the great stages already done

If Nintendo is able to do that, its make very sense that those games use same servers.

I don't want to interact with Wii U peasants once I have my NX. I completely disagree.

Yes. You can't ignore the 4-5 million olevels made on the WiiU version. And neither all the active Smash players on the WiiU.