I totally agree, but the poster wanted to use the favourites
Forgive me, I didn't read the entire post (this thread is getting quite long)
Favorites are actually called "ratings" internally in the XML, so perhaps Apple might expand them to include star ratings in upcoming versions.
However, Favorites are a range based "sub clip" feature, just like Keywords. However, they are limited in that they don't allow overlap, while keywords do. Keywords are also much more flexible because they allow the keywords themselves and their notes to be searchable and viewable in the timeline.
There is actually nothing that favorites (ratings) can do that keywords can't do. They are in fact a limited version of keywords.
See here in the event browser a 37 minute multicilp with use of star ratings and notes:
The story can be easily seen from these notes and ratings and an edit can be assembled in a timeline, and the notes still be searchable. Notice we had to let a few "1 stars" into the timeline: