J.D.
As for your older one, get her plenty of toys, like Leap products that teach her numbers and counting. Try to avoid sit down lessons. You can also play store with her. If she already has a cash register and shopping cart, that works great. Everything can cost a number of dollars, so she just counts out the money one by one. Have her watch Sesame Street. When my boys wash their hands I have them count to ten so they wash long enough. You can hold contests to see how many jumping jacks or whatever you can do in a row (counting). You can take flash cards from Wal Mart and put them on your fridge - numbers with the same number of pictured objects on them - just so she can see them every day.
As for your one year old, I think it is too early to worry about her development if that is all that is going on, but you can contact your local infants and toddlers program if you want and have her screened by Speech. OT, and a developmental ped. I think she is smart and she discovered what gets a reaction out of you (understandably!). Put her down, say no, and walk away every time she tries to hurt you. She will get the picture. Don't worry about the grunting - kids make all kinds of weird noises. I remember making weird noises as a kid just for fun. It may have looked disturbing to some unfamiliar onlooker. :)
J.