I have some of the same problems, and in my case I think it is caused by my old computer not being up to the tech recs. The problem with moving sims and time keep running, is when I travel. Sometimes I lose 2-3 hours just because of this. It happens only occasonally, it might relate to the size of the lot I travel from/to.
So, does your computer meet tech requirenents?
You could try starting a brandd new save, seeing if it will run more smoothly when there are less history/memory and files are smaller.
It could also be caused by CC and Mods. And, don't expect that a simple CC object can't make harm to loading and animations. In my game a CC bed caused sims not to be able to travel from their home lot - they had to walk out into thestreet for the phone option to work... Removing that CC bed solved it.
