> Potentially dumb question: once you own a certain percentage of public stock of a company, do they start contacting you for board meetings or decision-making of any kind?

Well, most decisions are outsourced to the board members, who's membership is the main thing shareholders vote on.

Mandatory reporting kicks in at 5 percent ownership. At 10 percent, the SEC considers you an insider[1]. Before that, I doubt board members even know you exist unless you talk to them first (and they aren't taking your calls or mine).

[1]: https://www.sec.gov/smallbusiness/goingpublic/officersanddir...