1. Taking le fait de out would render the sentence less understandable. Le fait de makes clear that what follows explains what means the scholarly expression motivation extrinsèque here while using the shorter qui est finalement répondre au besoin would have required the listener to think a little bit more to get what was meant.

2. Et donc is not a filler, it introduces a consequence.

3. Performer à travers cette prise de parole is the consequence of répondre au besoin.

I understand this excerpt to describe the gap that the person speaking experiences between:

1. her lack of internal motivation to elaborate on some sensitive subjects;
2. the social pressure leading her to actually elaborate on these subjects.