Is there any benefit to having a "parent" LLC managing other LLCs?

I don't see an advantage to this layout. In fact, it may be to your detriment having a common owner of the entities making them all easier to bring into a lawsuit. It also will cost you more to administer the extra LLC.

Disclaimer - This response does not constitute legal, accounting or other professional advice. Only through a personal, confidential consultation with qualified legal counsel can anyone properly evaluate their own unique legal challenges and determine what, if any, appropriate legal strategies and tactics should be implemented to meet those challenges.

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In addition to Mr. Lively's comments, limited liability entities not only insulate personal assets from the liabilities of a business, but also from the liabilities of other businesses. So, if you have two businesses with risks that you want to insulate from each other, you should place both businesses in separate limited liability entities, knowing that your organizational expenses will double. See you tax advisor regarding the owner draws.

My response does not constitute legal advice, as I do not know all of the relevant facts of your case, and I do not legally represent you. Although I strive to make sure the information I provide is generally accurate and useful, you should promptly consult an able lawyer who can learn the unique details of your case more completely in a confidential relationship to ensure that the information I provide, and your interpretation of it, is appropriate to your particular situation.