1. Is there any benefit for toddlers/children being read to? I always cancel this action because it seems time consuming with no value (that I know of).
None whatsoever.
2. Is it dangerous to use Rodney's death creator to set adult or teen to "die of old age"? I want some adult and teen ghosts that behave like normal ghosts and have fancy urn/tombstone.
Not that I know of.
3. Do I have to care about the zits on teen sims? Is there any effect?
Nope. And there's nothing you can really do about them afterwards, either. They just go away on their own. Sims can't actually amputate them in any way. The alleged treatment option in the mirror is actually a placebo, as it does not actually remove them.
4. What possibly caused my romance sim to want nothing but to dance? He has 7 loves now and each time the wants are rerolled all four slots are filled with "dance with".
Apparently, science has found that better dancers are more attractive.
5. When a sim is abducted, is the alien pregnancy decided at the start of abduction or when the sim is sent home?
I believe it occurs during the return sequence, because if something breaks in mid-abduction, nothing happens.