And wow, my phone screwed me on this one, didn't realise there were so many pages in reply
Just saw the band thing. What happens if it isn't the reliable source of income as you perceived from his end? Have you thought about being the band widow who is at home alone while he is out on tour all the time if they strike it big? And throw kids into that equation it can become harder. Without a doubt, people can do it and be happy, but can YOU?
Also the issue between a lot of band couples is of groupies if they get big... is that something you can handle? Even if he is not the kind of person to do something like that and you believe it now, will you believe it in another 5 years? Not all rumours are true, and there are people who do stay true to their SO, but even in those situations, jealousy can work in funny ways. Are you a jealous person? Could you become a jealous person over this?
I don't want to sound like I'm dumping all over your dreams but 'know thyself' is so important... especially when you commit to someone else.
Edit to add: PS. I believe in marriage, I really do. No one ever really marries believing they will get divorced... sometimes it just happens. I just say all this to make you think if you hadn't already. There is no point in you possibly making another divorce stat if it's all stuff that you hadn't come to think of yet