My understanding about the best friends is that if Generation 1 counts Generation 2 then Generation 2 could count Generation 1 but Generation 3 cannot count either. It would be better to do 1 & 2, 3 & 4, 5 & 6 and 7 & 8.
I'm with Seabody on the drums & piano supermaxing though. The Star opportunities are truly borked beyond repair as it's all based on the skill ops you get and if you want to get the Ops then I wouldn't have them learn any other skill so that's the only one that game can pull from. Example of why I'm sketchy: Did one of the 12 week challenges for Metro's tournament based around being a rock star. My sim only knew guitar as a skill and it still took 9 weeks to get the 10 opportunities for the Star Challenge. An immortal to be gets 3 weeks as a YA, 3 weeks as an adult and then you have maybe 3 weeks if you're lucky before Grim can come knocking. Without that challenge completed, this sim can't have ambrosia, life fruit or a death flower so they would literally be hoping to get the Op before Grim showed up. It's unnecessary stress and could cause you to fail. Especially if you happen to get it for one generation and then don't for the other. Alexandria had a serious issue with her ops coming in during her dynasty and did almost fail but had to switch to I think Nectar Making at age 81 or something.