I think one of the biggest challenges is playing University. Time doesn't stand still if you switch households like in previous iterations. You have to stay put through a full/half term or else your sim gets bad grades. I can count how many of my sims have completed a degree. Add the extra inconvenience of enrolling sims one at a time. I just find it so tedious since I like to switch households on a whim.
Manipulating the aging options is quite easy. I usually play with aging off or with aging the current household only. I let the aging bar fill up so siblings within the same age group aren't the "same age." If the age bar fills up I turn aging off until I'm ready to throw a birthday party.
With siblings living apart with families of their own, I have to remember to age them up in order lol. Just yesterday one of my sims turned into an elder after her baby brother because I forgot to age her up first.
As for elders, I turn aging on to let lived days accumulate or if I'm ready to let them pass on. Shortening the aging length if I'm in a hurry. Same thing with townies. Letting them pass on after some time to get new unplayed faces to edit.
As for pregnancies, I don't switch households until mom gives birth. So I can name the baby.
