When it's you who's gettind paid a bit late... it's manageable. When those late payments affect people you have to pay... it's a whole different game. I've been on both sides of this and it's great when it works, and bad when it doesn't. Building up a large buffer helps, but can take some time to get to an effective place that gets you more than a couple weeks of runway.
A few years back I tried forming an LLC with a couple friends, but they both have full-time jobs and they keep getting promoted, so it's never gone anywhere, and we're talking about winding it down. I'd love to try again with someone who is already independent and is ready to try something bigger.
I haven't read Developer Hegemony, but another great book about the dynamics of such a partnership is Managing the Professional Service Firm by David Maister. It's pretty dense, but it's full of great ideas.
I went into freelancing in part to avoid becoming a manager, and I think with the right kind of partnership you could still practice your craft while still helping to lead a small team of people---or maybe even just mostly collaborating with other partners. The Maister book has helpful things to say here about whether your firm focuses on work that is repeatable & leveragable (e.g. making Wordpress sites) vs unique, challenging, and done mostly by partners (which sounds more fun to me).
I'm in Portland, Oregon, if anyone is interested in talking about something like that. :-)
As for never being paid on time - I think the most late it's ever been has been 2 weeks. Pretty annoying but not the biggest deal in the world.