"If your the same age as me, maybe think about getting a managed server, so if anything goes wrong someone else does all the hard work"
I'm just slightly older than you, but no matter what age I would be to start a hosting company, I'd have a managed server. Having the manage a server yourself is even more work in my opinion, whereas if you have somebody ready to deal with any problems, it's much more quicker and efficient.
It's not just about start off though. It's about having a big knowledge of support issues. The host I'm at now, reading the forum on some support issues has made me think there is no way I could go into a hosting business. If you plan on picking up potential clients then they will put forward potential support issue questions, and it's up to you to help them out.
It's also great to have a large knowledge of a wide language of scripts, because at the end of the day, if a client needs some help with an HTML bug or a pHp matter, then it's you to you to help them out. Being able to help them out is another step to sucess, unable to help them out, well, that leaves the client opinionated on the service.
Oh, and as for your hosting business Jon, maybe you should get a managed server, because right now Fusion Hosting is not loading of me! :p