Blokada questions

Recently I installed Blokada. Look at the picture.

I have the following questions, perhaps someone knows an answer:

  1. What does the dimmed color of the line “android.clients.google.com” express? I added it to “blocked” but this entry remains green, why that? Interesting is: at the top of the display is a second entry also called “android.clients.google.com” - this one is red.

  2. I blocked the two “firebase”-entries. Is this good?

  3. I blocked also an entry called “mtalk.google.com” which is requested every few minutes. Who does this request? And for what?

  4. On the “Advanced” page is a menu entry named “Apps”. When you tap on it the installed apps are listed. Then you have an option on each app to “bypass” this app. What does this mean, exclude from Blokada?

  5. What else would be good to block?