The civilian shipping tends to do good with colony ships and cargo ships, eventually.  I usually don't bother with colony ships of my own, I just make a design and let the civilians handle it.  A bit slower, but meh, they do the work for me.

yes, BP on the ship summary is the cost that the civilian company pays to build their ship.

Well that's not the problem then.

Build points?

First, check the build cost of your designs is less than the shipping lines available funds.   
Second build a freighter of your own and some infrastructure (build the infrastructure yourself from the industries tab) and move it to a colonizable world.    I'm not entirely certain but I think that civ lines don't look at supply and demand contracts and decide to build a ship to fulfill them.    Instead they need to see a situation that they can fulfill that is already present, such as available space for colonists on another world.   

Yeah, I figured they might, that's why I put a population on titan, to spur them into doing something, but it didn't.   

Uh, noob question, how can I tell how much my designs cost a company? I think that might be the reason (the design by this stage is pretty big for a start up company I guess), and I'd be happy to subsidise them up to the required wealth level, but I don't know how much it would cost them.   

First, check the build cost of your designs is less than the shipping lines available funds.
Second build a freighter of your own and some infrastructure (build the infrastructure yourself from the industries tab) and move it to a colonizable world. I'm not entirely certain but I think that civ lines don't look at supply and demand contracts and decide to build a ship to fulfill them. Instead they need to see a situation that they can fulfill that is already present, such as available space for colonists on another world.

Ah, I guess I never got so far ahead that my economy was in trouble!  I was always planning to make Mars into a paradise world for the custom species "Marzoids" and have them produce all my monies (or a lot, at least) because Mars has no minerals to speak of.  I'll keep that in mind though, to get a growing economy...

Everything you do costs some cashmoneydollars.  So when you're doing your early buildup, taxes cover everything nicely.  Once you research the industry techs-- research rate, construction rate, mining rate-- each installation is now consuming 20% more cashmoneydollars for each bit of output!   Once you get some serious factories put together and a lot of research bases, we're talking about some SERIOUS increase in expenditure.

I've generally seen my money building steadily, then PLUMMETING to crisis levels.  Financial installations generate cash equal to about 1 million people, so they're a great way for breaking even when populations are low.  They also cannot be moved.  As you extinguish mining worlds of their hard resources, consider dropping off some construction factories and requisite material to gradually convert the planet to a financial world.  Those places will generate BOATLOADS of cashmoneydollars.

I've not quite understood the importance of economy yet.  I know that you get taxes and such from colonies, and that research stations use these taxes, but what do they do otherwise?  What's the important of the cash economy?  I've been entirely concerned about the hard resource economy of moving mines and building ships.