I've been hearing about the problems with the economy, but haven't experienced it personally. I've played pretty far into several games on this version now, all on Gigantic at Challenging. All of them as the Krynn. Generally I cruise along at 200 bc to 1000bc a turn without any of the tourism or tax mega events.
I do keep up with my trading, I have the max trade routes possible as a neutral Civ, again without any mega events or special votes.
I put as many of my ability points into economics as possible at the start, and I pretty much run through the whole game at 100% with research set to 45% without ever having to alter those except early on as I build my economy.
I also put a number of stock markets on my planets, and layer my trade routes with economic star bases.
In my most recent game, I've generally stuck at around 500bc per turn, but I do have two economic resources with max modules going. My Navy consists currently of about 10 medium very well armed ships, 3 large very well armed ships, and about 20 small very well armed planetary defenders. Essentially I have about the strongest military.
The Small ships are about 9bc/ea. The Mediums are about 20bc/ea. The Large are exactly 48bc/ea. I also have a number of miners and constructers roaming around/building/etc, but couldn't even guess how many without looking. So I'm spending a lot on my ships, personally I agree, I think we are paying far too much, especially when constructors are costing 8bc or so each. That's ridiculous.
My point is, I think it is possible to survive as things are, even without economic resources, but it would be nice to see some of the ship costs go down to help balance things out a bit more. I think I read some suggestions regarding tourism too, that definitely needs to be tweaked. In many real economics, tourism is a major source of income, but here even with nearly a sixth of a gigantic galaxy under control your lucky to pull in even 100bc.