Understanding「そうなるとやはり犯罪者かしかしあまり大物でもマズい」


From the first episode of _Death Note_ , I'm having trouble understanding

> そうなると やはり犯罪者か しかし あまり大物でもマズい

  1. Why is there a と after そうなる?
  2. Is やはり's reading "矢張り"?
  3. Is あまり's reading "余り"?
  4. What does this sentence mean?




> Why is there a と after そうなる?

[そうなると](https://jisho.org/search/%E3%81%9D%E3%81%86%E3%81%AA%E3%82%8B%E3%81%A8)
is a set expression meaning "if that is the case", "if it becomes so", or
"when it becomes so".

> Is やはり's reading "矢張り"?

Yes, this is 矢張り but it's almost always written with kana alone.
[やっぱり](https://jisho.org/search/%E3%82%84%E3%81%A3%E3%81%B1%E3%82%8A) is also
commonly used but it's more informal. Additional details can be found on [this
post](https://japanese.stackexchange.com/questions/418/whats-the-difference-
in-usage-and-nuance-
between-%E3%82%84%E3%81%AF%E3%82%8A-and-%E3%82%84%E3%81%A3%E3%81%B1%E3%82%8A).

> Is あまり's reading "余り"?

Yes, あまり is 余り.

> What does this sentence mean?

Here is my translation (disclaimer: I'm not a native speaker):

> If that's the case, it should be a criminal. But someone too important would
> be bad.

I also looked up the official translation from the English subtitles which is
the following:

> In which case, the victim should probably be a criminal. But it can't be
> someone too infamous.

