Both are correct but worded awkwardly. Try this: I hope we can finish it by the end of these two days.

1 (2); 2 (2)

It seems to be asking whether you have any family members who are NOT Australian citizens.

Perhaps you mean "as easy as pie" which means something that can be done very easily.

Without more context it's impossible to say. "Cheap flights bug" reads like somebody enjoys taking low-priced flights.

Apparently it's a reference to the Brixton Splash of 2015 where celebrants left behind large quantities of foul-smelling garbage. Here's a link. http://www.standard.co.uk/news/london/brixton-splash-bins-left-overflowing-with-disgusting-rubbish-hours-after-the-end-of-the-festival-10435270.html

I used Google to translate your question so I'm not sure I fully understand it but I'll try anyway. The modal "might" indicates a significant amount of doubt as to whether something is going to happen. The modal "could" indicates a stronger probability but not a certainty. Here are two examples: A) John might fly to New York. B) John could fly to New York. In sentence A, the possibility of John flying to New York exists but the probability is weak. In sentence B, the probability is stronger but not certain.

Yes, "how are you" is very much like saying hello. Although it's grammatically a question, its use in America is so widespread that nobody bothers to answer the question. The customary response to "how are you" in America is hi or hello.