[lubuntu] Can someone please explain what do the fcitx options mean?

Hi all,

I recently upgraded to Lubuntu 16.04 and I am trying to install a second language in my OS (greek) and enable switching between the two.

I unfortunately hit a roadblock with the name of fcitx. It looks like the person that wrote it in English doesn't have the best command of the English language and the names of the options don't make much sense. Another problem is that there is no documentation on the options which is the reason why I have come here for help.

I would be grateful if someone can explain what each option does or if he can answer as many of the following questions
Hotkey tab
What is an input method?
What is the trigger of input method?
What is the point of the extra key?
Why activate and deactivate input method?
Why enable hotkey to scroll between input method?
What is include inactivate when scrolling between input method?
Why do we need a custom switch key when there is a scroll between input method? What does the custom switch do?
What does the reload configuration do?
What is the interval of the two key input?
Why do we need the virtual keyboard?
What is Remind Mode?
What is the switching full width character mode?
What is SwitchFull Width Punc Mode?
Why do we need to move between pages?
What are second and third candidate words?
What is the embedded Preedit?
Why do we need previous and next candidate words?

You can guess that I don't understand much from the other tabs as well. And I couldn't find any relevant at least documentation on the subject.

Can someone please help with at least some of these questions?

Cheers,

Satrapes