Huh? You're using two SCOTUS cases specifically about the second amendment to prove that the 14th amendment applies only to guns? What about
Brown v. Board of Education? That's about schools but the equal protection clause of the fourteenth amendment applied heavily in that ruling.
Or what about
Gitlow v. New York, a case which utilized the fourteenth amendment's incorporation clause to apply the right to freedom of speech to the states?
The citizen portion of the fourteenth amendment is clearly not about guns, take any case related to that portion and it will be about anything but firearms.
The due process clause applies our right to life, liberty, and property directly against the states (despite the fact that it exists already in the fifth amendment). While it could certainly be argued that our right to life, liberty and property exist thanks to the second amendment, it is used to prevent our government from infringing on any of our rights. Take
Roe v. Wade for instance, the third holding directly cites the due process clause of the fourteenth amendment.
Maybe wikipedia is the wrong place to look? I would assume that it would be there if the fourteenth existed to apply the second amendment to freed slaves. I would also imagine that something would have been done about the
continued denial of firearms to blacks after the fourteenth amendment was passed. It's kind of a huge failure of an amendment if it failed to have any impact at all until the mid 20th century.