1. The last time I had permanent dye in my hair was when I was 38 and it was some highlights to camouflage the few gray strands I had started getting.
2. I remember my hair was pretty damaged after that and at 41, I did a big chop. It was healthy, but i was using sulfates and 'cones. Fast forward another nine years and I am now six months CG and my hair is very healthy.
A few years ago (post separation/divorce at 44/45 years old), I read "Going Gray" by Anne Kreamer; I highly recommend this book.