How useful is studying MSc Computer Science in Switzerland? I am an international student in Australia studying Bachelor of IT.
Australian education system as the norm here is to take 4 subjects per semester and these subjects are pretty much "dumbed down". So a lot of subjects don't really teach much, for instance for Algorithms and Data Structures subject we weren't taught complexity at all, so during technical interviews for my internships, I was not able to give any answers in regarding to complexity. 

Now this will be my last semester, and I feel like I still need more coursework for Computer Science and spending more money for Australian universities just sounds ridiculous at this step. Since almost all US and UK universities need honours award from Australian degrees (and that's extra $26k), I will not be applying to any US universities . I applied to one UK university that never mentioned requirement of honours and got rejection. I have applied to UBC in Canada but it will also cost me about CA$15-20k/y. So I had a look at European universities and found out that German and Swiss universities charges about 500-600 Euros per year. I found out that most German reputable universities don't really offer fully English Masters degrees in Computer Science, however that's not the case. ETH Zurich prefers students with honours as well. I found that EPFL has a good education and I would like to study Distributed Systems, which they offer quite a lot subjects on that, however what concerns me is after graduation job security. As I mentioned, my purpose of studying Computer Science is not to become an academia but to have stronger Computer Science skills.

Anyway so far it sounded like very specific, but my question is not that specific. Would it really worth studying Computer Science in Switzerland, with the consideration of graduate job prospects as well as doing internships and the fact that I don't have EU citizenship? I know that Google would accept international grads, but are there many companies like that?
EPFL is one of the better technical universities. This has two consequences: 1) it will be hard (as @xLeitix notes, if your current school doesn't even teach complexity, you will be in for a challenging time at EPFL), and 2) you won't have a problem to get a job afterwards.

Note that differences between schools are not as pronounced in Europe as elsewhere. For instance, I am pretty sure that you will not be able to attend a German or Swiss university without exposure to algorithm complexity. Consequently, employers (both academic and industry) in Europe don't really care all that much about school quality. Grades, internships and the impression you leave at the interview are much more important.

Beware of costs of living in Zurich. Zurich compares with New York City. It's horrendous. (I used to live there.) Lausanne should be somewhat better, but Switzerland is generally an expensive place. If you seriously plan on going there, check local rents and/or supermarkets (coop.ch or migros.ch - you should be able to find this week's offers even without speaking German) and convert them from CHF to AUD to get an impression.

Note the language: Zurich is German-speaking, but Swiss German is very hard for a non-native speaker, even if you did take German classes. Lausanne is French-speaking, and the Swiss French is closer to "standard" French than Swiss German is to German. Francophones dislike speaking English, so you will get by more easily in Zurich than in Lausanne in English.

Switzerland is not in the EU (although it of course cooperates), so your EU membership is not all that important. With an ETH/EPFL diploma, you should have no problem getting a job anywhere in Switzerland or the EU.