The good news is that two of the affected households "calmed down" and don't show the strange blaster behaviour anymore. The third household has many Batuu objects (including debug ones) on it, so there may be some interaction that cause the blaster spawning.
On the downside, I still don't get the autonomy per sim to work in McTuner. I clicked on Chris, then the MC menu on him, then McTuner->Activate autonomy scan and then a shower. Took away all shower actions. However, that also prevented his wife from showering. I then activated autonomy scan for Susan, clicked on the shower, allowed shower autonomy for her - bamm, it was also allowed for Chris again.
So it's still an all or nothing deal for my sims. I don't know what I'm doing wrong.
