Nope, eating is necessary for staying alive. Reproduction isnt. Following your own reasoning here, celibacy would be a disorder as well. Since celibacy unnaturally (at least according to your simplistic understanding of human sexuality) disrupts a man or a woman from acting on their natural sexual drive for reproduction for religious reasons. Sure, you can cite scripture and what not to get some support for celibacy, but you made an argument from nature.
Celibacy is a choice. It's not a psychological aversion.
To go with the analogy to eating - anorexia is not the same as fasting.
Of course, your argument does not succeed anyway. It assumes that sexuality and reproduction is all about the individual procreating, but biology talks about the sexual fitness of a population as well as that of an individual. A groups ability to reproduce is in some cases more important than that of every single individual within the group. And human beings are social animals, in other words group animals. So it does follow that individuals that do not reproduce are disorderly, they may have (or had) a function that aids the survivability of the group and thus the reproductive fitness of the group as a whole. Then your entire reason for calling it disorderly is false.
Sure, certain disorderly behaviors in individuals
could help the species. But that wouldn't make the individual less disordered. For example, I bet rape has played a big part in human survival during certain points in history (and pre-history). But I'd still call rape disorderly - wouldn't you?
Since homosexuality exists in other social animals as well, it kind of supports the idea that it does (or has in the past) support the overall reproductive fitness of groups (I personally think that is a better explanation than postulating that the devil and his minions goes around tempting certain individuals, including penguins for some reason, to desire the same sex), and then it is actually the opposite of disorderly, its beneficial and orderly if reproduction is your criteria.
And how do you know the species survived
because of those disordered behaviors, rather than
in spite of them?
Plenty of disorderly behaviors (pica, pedophilia, kleptomania, etc) are present in our species - they've been successfully passed along throughout or evolution - but they're still disorders. Right?