When group admins receive complaints, how often does this mean that the member will be removed and blocked from their groups?

In your case, Felicia-Ben (are you male or female?), the administrator made it very clear that you are both removed and blocked ... forever.

If the other members are complaining about you, it's a one hundred percent certainty that you'll be removed from the group. 

That depends on the rules of that group and the level of tolerance of the admin(s) making the decision. It won't be the same across all groups because different ones have different rules, and the person or people running those groups may or may not be very strict about what is and isn't allowed. 

In your case, yes, that's exactly what it meant - you were removed and blocked.

Depends on the rules the group follows, I have seen people muted for a month for being rude for a first offense and kicked off for a second or a more serious infraction

There is no way to know, each moderator is different.