If anyone else is wondering about using Wine I can give them some advice from my experience.
I believe Wine itself should be safe, so long as you don't download odd things from the internet, etc., and I'd recommend to only run it when your internet connection is turned off.
With that said, I installed Wine on my 2006 MacBook, and experienced very poor results. I am pretty sure the blame is on the MacBook, and not Wine.
Wine itself works fine on the MacBook, but when trying to run any Windows program, particularly games, it didn't work all the way through. The installers worked, and even parts of the games worked, but they all had different problems (I was using Wine v. 1.6.1). Even games which on the official Wine website are said to work on every version of Wine, for every OS, did not work at all. All in all I believe the MacBook's the problem. Being they are not built as professional machines, they might be lacking the internal hardware necessary to properly run Wine all the way through.
So to summarize, Wine is very tricky to use and you will be much better off using an actual Windows computer. However, if you're a Mac person that really hates Windows, you could try Wine, but I would not recommend it unless it was completely necessary. Also, Wine is not advisable to anyone using a regular MacBook, as it probably won't work.