If I might have played with baby powder when I was a kid around 1996-1997, and I might even inhaled or huffed it (no way to remember now, I was 6 years old), how concern should I be?
The smallest amount of concern possible. The scientific record is mixed. Some studies find a small effect and others find no statistically significant link. Worst case scenario is 5ish additional cases of ovarian cancer in 100,000 people.
AFAIK no link has been shown between lung cancer and talc. Likely none exists. Lung cancer links to stuff like Asbestos is limited to people like miners and factory workers who breathed the stuff in all day every day for decades. But generally speaking particulates are linked to lung cancer and other lung issues. Probably best to not breathe in clouds of the stuff but I wouldn't worry about normal usage.
My concern would be mostly on the issue of asbestos contamination. I tried to find if there is any known contamination issue in the 90s, but my google-fu got nothing.
These lawsuits are from people who developed ovarian cancer after regularly using talcum powder for years or decades. Maybe your youthful use of talcum powder gave you an ever so slightly higher chance of developing lung cancer, but it's generally regular exposure that causes problems. I wouldn't be concerned.
Brake pads were made of, not just possibly-contaminated-with, asbestos in that era, so assuming you lived somewhere with cars it wouldn't be a significant source.
(but don't inhale rocks, they are bad for your lungs)
Yeah I went down the asbestos rabbit hole a few years ago. It is insane how much stuff was made with it. There’s basically a non-zero background level at all time
