In this case, the other information is 1) proven credentials in the subject matter and 2) general acceptance of his theories by a community with more credentials. He lacks the former and the latter, so I'm disinclined to give his theories much attention.
Plenty of so-called outsiders have made amazing discoveries before, or at least hypothesized what would eventually be an amazing discovery. Maybe that's the case here. Yet skepticism seems warranted without that being considered an ad hominem attack.
Really a fallacy represents a particular weak argument. The way to defeat them is not to name the correct fallacy but to point out the weakness.
If that doesn't work then you likely have the wrong fallacy, or the argument isn't fallacious to begin with.
But like contravariant said, that doesn't mean the argument is wrong—just that it's a weak argument.
Astrophysics is not a matter of personal opinion. It requires a lot of detailed knowledge and careful practice. Legitimate authority is relevant.
I am no expert but that wacky idea can be ruled out with concepts in an introductory physics textbook just based on the fact that the cosmic microwave background is a few Kelvin blackbody spectrum whereas the ocean temperature is 273K or higher (which would have a very different "warmer" spectrum).
And God! What a convoluted theory full of ideas nobody can test.
Metal hydrogen is a liquid though, it doesn’t form a crystalline structure like an actual metal.
It isn't surprising that there is messy magnetic field when Sun is pure conductor.
Metallic hydrogen probably has something to do with magnetic field on Jupiter.
The summary is that the sun is actually metallic hydrogen, which forms a lattice similar to layers of graphite. This both explains the black-body radiation of the sun and provides a mechanism to explain sunspots and the solar maximum and pole flip: sunspots are non-hydrogen elements that are excluded from the metallic hydrogen lattice and push it upwards as they migrate to the surface and are ejected.