Also don't discount the fact that all of the unacceptable shit that grandma is doing, was probably socially acceptable back when they were raising their own babies(you)
The Do's and Don'ts of raising a baby have changed drastically in the last 30 years, she may just be doing what she knows. She probably hasn't had a reason to keep up on the newest baby-raising techniques and changes in the decades in-between raising you, and now watching your baby.
Hell, I was born in the 70s, so I slept on my stomach, I got solid food starting at like 3 weeks, my mother smoked around me, etc. It's a miracle any of us survived
Now that my mother watches my child 5 days a week, she's had to adjust. She still occasionally lets him sleep on his stomach, if he just does it while napping and in the same room as her so she can keep a close eye on him and I'm ok with that. Stomach in the crib is a no-no. She does go outside to smoke, and doesn't really smell like smoke since it's only 2 or 3 times a day.
Just work with your mom. I'm sure she loves her new grandchild, she may just be ignorant of all the newest baby-raising information and techniques.