Are authors of papers okay with receiving questions from people in industry?
I certainly don't see anything immoral about asking questions.  You may want to mention your affiliation, which will clarify the issue and perhaps also help the author give a more useful response.

The author doesn't have any particular obligation to respond to your questions or anyone else's, but probably will if they are interesting and well thought out.  Academics generally would want to encourage anyone who is interested in their work.

If your questions get very involved, to the point where an academic might consider suggesting a collaboration, you may want to consider offering the author a consultant contract.