I have a few questions which may have been addressed before, but since the topic is so long...
1) "Each of the stages’ pieces need to be added to the museum before an immortal would age up to the next stage. "
The rules are all the time talking about a museum, but my sims won't be able to afford one for a long time. I always want to challenge myself and I'm testing, if this challenge is doable without going the "Agnes route". So my founder married a regular townie, who brought in ca 5000 simoleans. No other townies have moved in, so it's just the regular family members, who have to accomplish all the requirements. Now the family is so poor, that they live in a shack and cannot afford to build a museum. So the portraits hang on their kitchen walls (at least they have walls!). So is it OK to build the museum later and move the portraits?
2) "Optional: Photographs and/or ice sculptures of each immortal at the same life stages may be included in the museum"
I was lucky to buy a camera at the consignment store, so I will have both paintings and photos of the immortals in each life stage. But since the spouse had to learn to paint portraits first, she did not master sculpting to make non-melting ice sculptures before the founder was an adult and the heir was a teen (she did make the ice sculptures for every life stage, but they melt). Will it be OK to count the values of the remaining ice sculptures even if I don't have a complete collection, since the sculptures are optional?
3) "Immortals can have overlap in their opportunities that they do, as long as they have accomplished 6 unique ones."
Does that mean that e.g. all the kids can go to the free game or repair the boiler at school as long as I don't claim it as one of the 6 unique opportunities for any of them?
4) "Travelling is banned until the 2nd generation becomes Young Adult."
I think I got this right, but just wanted to make sure I don't confuse this with the concept of heirs in the DecaDynasty: you cannot travel before the first child born in this dynasty (who will be the second immortal) is a young adult?
5) About the Lifetime Rewards: Any Lifetime Rewards the mortals buy don't count, so the spouse can buy e.g. the collection helper or the moodlet manager?
6) About the 6 best friends: If my founder has his spouse, his daughter (=the second immortal) + four other best friends, can the daughter claim the founder as one of her best friends?