You can buy fake facebook followers but those accounts will remain idle and in long run will do no help for you.
They are somehow good. It makes your page look popular. But be carefull, I know a person who bought 10.000 likes and in 3 weeks they were all gone.
I don't think buying FB fans or likes will do you any harm... Unless you buy a billion in a month... Buying google plus ones, however, is exactly what you should avoid...
I don't think Facebook fake account would be harming your page. Still be safe from slut Facebook fan who is unpleasant. This is the way where your account can be kept safe from dirty people. Don't worry about the rest issue's.
I'd say it's only a reputation issue - if your visitors check your "likers" and see only some fake profiles or "pay-per-clickers" I doubt they will be still interested in your FB page...
I do not think if your fan page is getting likes in a normal growth, no issues even if it is fake. If you are planing to increase the Facebook fans count rapidly, I am sure FB will notice it and they may punish. I don't think anyone can harm your fans page for simply allowing them to press like button on your FB fans page unless you give them access to your account.
Fake followers will give wrong impression.It does look like that the page has a lot of followers but in my point of view its not going to give any positive result.