Dynasties and Affinity traits

I just read up on dynasty traits, and especially the affinity traits stands out as a bit different from the rest. I now wonder how you all use this feature for your dynasty members to benefit from?

Pointing at those icons in the UI tells that these traits come in 3 grades, if I get it correctly, a sim can only get the 2nd grade affinity trait if born to a sim holding the 1st grade. The 2nd grade holder will again pass on a 3rd grade affinity trait version (the strongest) to its children. So, it seems to be a 3 generations thing, which might be long enough to most of us. But I have some questions...

1. What do the kids of a 3rd grade affinity trait holder get (4th generation)?  Will they simply get to keep the 3rd grade version, or will they get nothing?

2. What happens if a sim, say holding the 2nd grade version leaves the dynasy. Will their kids still inherit the 3rd grade, or are they benefited only while the parent is a member of that dynasty?

3. Any benefits from this feature that is not so easy to spot? How can a dynasty best benefit from Creativity, Mental, Physical and Social? Any not-so-obvious cross pack details?

Did anyone explore this feature in detal? Lets share what we find! :)