I had something much more weighty partially written, but the effort was high, and the subject matter is so easily dismissable it wasn't worth the effort.
Firstly, Erik presumably wrote his post in an effort to persuade people, or at least to get people to discuss his ideas. Throwing semantically loaded terms such as "racist" and "Muslim" into the post was thus very self-defeating; any mention of those terms is going to raise strong emotional responses in most people, regardless of the context in which they are used and the actual message being conveyed. That this is true is self-evident - I've only seen two responses to Erik's post, but both essentially ignored the actual content of his message and responded instead to the semantic weight of the terms "racist" and "Muslim". Both terms are unneccessasry, and Erik's message would have been more clear if he'd avoided such weighted language.
Secondly: shorn of weighted language, Erik's argument is this:
lets consider an imaginary totalitarian political ... that advocates the overthrow of all current governments and rulers with the aim of replacing them with a head state who would rule according to doctrines of a utopian philosopher ... With the above in mind, I think it is reasonable to ... vet ... all immigrants. Any that do not agree to hold Australia's laws and constitution above their religion (regardless of what that religion may be) should not be allowed entry
Erik assumes that it is possibly to vet immigrants to determine which will "hold Australia's laws and constitution above their religion". Given that we've seen plenty of examples of extremists willing to become suicide bombers for their cause - even for non-religious causes - I find it very hard to believe that any cause would find it difficult to attract people willing to lie about their intentions for long enough to gain entry to a country.
Further reading of Erik's post reveal the he is conflating three distinct concepts: entry to the country, residency, and citizenship. Until Erik can untangle those three, I'm not going to try to argue comprehensively against them, as any such argument would first have to disentangle the three and deal with each separately, and I'd like to get to sleep sometime sooner than next three or four hours.
I will say that I find this idea repulsive. Even if such a test could be devised, it would result in penalizing people on the basis of actions that they may commit in the future. Such a notion is completely antithetical to the kind of society Erik seems to want to live on.
On that topic, Erik makes an egregious error of definition - particularly egregious given that he started the post by disputing a definition. Erik says that:
The ideas behind democracy is not one of the majority imposing its will on the minority.
I'm sorry, but I don't believe that's not the case: as far as I understand it, democracy does, indeed, mean the exactly that. The idea that the majority should not unduly impose it's will on the minority is, as far as I know - liberal democracy. Admittedly, the word democracy has come to imply, in our culture, in this time, liberal democracy - but if one is going to be so pedantic as to waste time arguing about what category of hate speech one is spouting, I think it's only fit that one also be so pedantic as to properly define the ideal toward which one is aiming, rather than relying on the shorthand that one wastes so much time railing against in other areas. If you feel I'm wrong, please feel free to tell my why I'm wrong - but that, perhaps, should be a separate debate, as I feel it's going to touch on areas of linguistics and semantics quite disjoint from the main topic.
 Except, of course, pedants. However, even pedants will merely, at best, agree with your classification of this particular bit of hate speech - but it's still hate speech, and thus vile, and thus your exercise is wasted.
 cf: Paragraph 10, a discussion of requirements to obtain Dutch residency, and Note 1, which refers to a "democratic" destruction of the political system. Merely having a majority of residents couldn't achieve this, as residents are not entitled to vote; this would require a majority of citizens to support the cause.