I've done only two play-throughs, so let me know if I am totally wrong here, but it sure seems to me things get wildly out of control in the second-to-last and last age in the test, especially in generating money.

Obviously you need more money to pay for bigger buildings, so 1 gold in era 1 is not the same as 1 gold in era 4.

That said you go from something like +4-6 gold on a merchant to Phoenicia's special building for ~+10 gold (and an earlier tech) and that's... nice? 

To: Carthage... which doesn't give you any money but decreases buyout costs by 50% (which... I have no idea if it stacks with Phoenicia) 

To: Ghana where you're generating 30 or more gold per territory (Really heating up!)

To: Dutch  where you can easily generate over 100 gold per territory (Welcome to insanity!)

Meanwhile the sad Merchant Quarter barely goes up at all even with lots of trade and tech. Anyway, long story short is money seems to ramp up to insanely fast with Ghana and Dutch cultures, amplified by the earlier two. Just seems a little out of control. At one point I added an independent nation to my side and literally near-instantly filled up almost every piece of land in the territory because... why not? What else am I supposed to do with 20 grand?

This was on the second to max difficulty.

So the question is: Does this happen with science or production as well? I certainly saw something similar with food with Celts, but didn't take it to the full fruition (which I think would be going Phoenicia -> Celt -> Viking) to maximize how many harbors you can get. Each harbor generating... well, an insane amount of food. 

The short answer is: Yes and I believe that's on purpose.

Longer version:

Yes, you can rack up insane food (harappan start is actually better for overall food production. You can also rack up insane science (honestly just need Zhou and either joseon and your science will be insane). You can similarly have your influence go through the roof (mauryans and I can't remember the other 2 civs).

I believe this was done on purpose for 4 reasons:

1) Most other games make advancing from one age to the next seem pretty linear, when the reality was that the early ages were all fairly similar and then suddenly tech started speeding up exponentially and things started spiraling out of control.

2) It offers a good balancing point against trying to stay in eras longer to produce more fame from stars, since you can rush down certain play styles and just straight-up eliminate a player from contention if they try and stall out any of the eras too long, aside from neolithic. Neolitihic of course, the traits and free troops end up being a pretty massive advantage that more than makes up for claiming all 3 stars.

3) It allows for more dynamic culture combinations (going carthage into a military culture for example to allow you instantly buyout beefed up armies).

4) It makes the various playstyles all seem really strong without actually throwing the balance too out of whack. Players feel rewarded for picking a particular culture because it does exactly what they picked it to do (e.g., Dutch make any money worries disappear). If you picked the Dutch because you want to make lots of money, then it would feel bad to have an aesthete culture outpace your income (unless they completely threw away their influence production to do so).