I'm looking for a 2 kinds of triggers:

1. That sends the administrator an email when a member changed a specific profile-field.
That field has 2 states, say A and B. Default is A, but when a member edits and changes it in his profile to B, an email had to be send to the admin.

2. Our CB website had a silent registration.
So admins do not have to activate new users.
But the admin should receive an email, when a new member registers to the community with the B-option selected. (B is referring to the previous 2-state field)

Please advise

Believe incubator project CB Profile Update Logger does all this for you. Otherwise you could use CB Auto Actions to do this after the profile update trigger then check if [FIELDNAME] is not equal to [var3_FIELDNAME]) (I think it's var3, I can't recall; maybe var4).
You should still get new registration emails assuming you've CB configured within CB > Configuration > Moderation to send moderator emails. You'd then need to edit your user in CB > User Management and set your user to receive moderator emails. Alternatively CB Auto Actions with an email action using the after registration trigger can do this.