How will a divorce affect stock ownership in a closely held business.?

Answer 1

The stock held by the ex-spouse can be sold back to the other stock holders and this is often the case in smaller companies, so they are "cashed out" of the business end of things completely.
As for daily operations, often they are not positively or adversly affected.

Answer 2

There may soon be a new stockholder who doesn't work at the company...