Over the years, I've had this discussion with business owners. What privacy settings should you use when you have a Facebook page? The other question centers on who you should allow as a "friend" and should it only be people you really know? I'm going to provide my opinion to each question:
Privacy Settings--people who are in business for themselves and promote any material with their actual names on it should never set privacy settings to the strictest levels, which is only friends can see your page. If you use your name on your marketing materials (and this applies to authors in particular) then your "fans" are going to search by your name. The whole point of social media (more important than using it to socializing if you're a business person) is to network and connect with others. Locking down your page and preventing others from reading your Wall puts a barrier between you and your audience. Potential connections who are trying to size up your business and understand if they should reach out to you won't be able to see anything posted. Now one might argue, but I have a fan page and I want to restrict my personal page. Well, my response to that argument if you have a "name" is that people are still going to search for your name to friend you. If you desire to keep personal information personal and private -- and you have a well-known name -- my suggestion is to tweak your name just enough and switch over to a strictly personal page and keep your professional page out in the public eye. The bottom line: you do not want any barriers with your prospective clients, customers or fans.
The real meaning of "friends" -- my joke is 3500 of my nearest and dearest. I accept everyone who reaches out to me. I started with 200 connections and the other 3300 reached out to me not the other way around. In fact, I don't friend anyone these days. In the early days the argument was, "I only friend those people I know." But in the networking world that argument fails. You don't know why someone has friended you in the first place. Are they an author looking for a home? Are they a potential marketing and PR client? If I reject their "friendship" that answer will never be given. Some prospective clients will check out my posts for a year or more before they bring me their business. If I closed off my page to true friends I would lose potential business. The bottom line again is I am a business person, and I am using social media to do business. Yes, it's fun at times, but I'm not on it to socialize. If I want to socialize I will create a secondary personal page under a tweaked name and keep my personal friends ... my real friends in that ecosystem. However, I don't think it matters. I just keep my content relatively impersonal to protect my privacy and keep a fan page for 3L Publishing.