Bedeutung: Gegriffene Bässe??

[Cocoonair]

Guten Abend. Danke für eure Antworten. Meine Partnerin hat noch ein paar
Fragen und da das Ganze für mich zu kompliziert wird so schreibt sie nun direkt
auf Englisch - ich hoffe das ist in Ordnung - Dankeschön:

Thank you so much for your responses as well as the link, it is really
greatly appreciated. I unfortunately can't yet play from notes and am
struggling a little bit with my limited knowledge of music theory. There
are also no guitar teachers near where we live and I'm getting more and
more confused with the more that I read online . If my questions are
too hard to understand I can try to reformulate them (in German if
necessary)

After reading your response, I researched online and found this diagram:



Which corresponds to your response "A Bass Note of C may be picked at the
A string on the third fret", but I still have a few questions:

1.) In the video that you posted, is the woman playing chords or notes? I
noticed that she played a C chord, but don't recognize everything that she
does with her left hand.

2.) Is it correct, that when one plays a C chord, it is possible to pluck the E
string (open) with the thumb before strumming or finger picking; and that
the string which is plucked changes depending on which chord is played? Is
this simply a playing technique, which has nothing to do with "...gegriffenen
Bässen"?

3.) Are there set rules to which string should be plucked for which chord?

4.) Would "spielen mit gegriffen Bässen" be - for example - playing a D chord,
then plucking the D string whilst holding it down on the first fret, then
playing a G, plucking the A string whilst holding it down on the third
fret...etc.?

Thankyou in advance!