In this case, "all" is more like "completely" in meaning, and "too" makes a large amount negative, so "all too" means it is completely and unfortunately fleeting.

In this case, i think it means that they did not squabble. If i wanted to say that there were squabbles, I would say "not so petty" to focus the negative on the adjective.

Good question! In the US, it is common enough that most people know it but almost never use it. It sounds very old-fashioned, like from Shakespeare, and most people only use it as a joke. I would say "three times".

My favorite series

All day long I was watching a series called Mr Robot. The story focuses on a hacker that
seeks to destroy the system from a computer.
This serie like him for its topic, and I can identify with the principal character, and that's why I like it.

"from" in this case is okay, but "using" sounds a bit more natural to me.

Also, i would say "I like this series for its topic" for the second part. 

The other parts are good!

p.s. I loved Mr. Robot. Great show! :)

Yes, if you say "book" or "article" etc. If you only use the title than you don't need it. "the book 'Das Kapital' was published in..." or "'Das Kapital' was published in..." either one is okay.

hardly a several day story: the topic is not very important so it wont be talked about for very long. at that point in time: that specific moment, not always. gist: this is the main point of the topic, so in this case, give us something else to argue about. slopping up: this is a negative phrase for eating a lot quickly. in this case they main taking in a lot of information without thinking. pretty negative way to say the other person believes anything they hear that agrees with them.