the result of this is that Iridia is now producing 103k wealth per turn
Actually you arrive at 103k wealth per turn only because the economic star base module bug is still in the game. If you correct for this bug the wealth generated will be (102995.2 * 3.85 / 5.6 + 230 - 122.7 = 70916.5) about 71k per turn.
Furthermore Iridia is a massive planet (after terraforming) therefor the adjacency bonuses come (exponentially) into play for the production on top of the larger - than average - number of improvements. And it was already known that ridiculous manufacturing planets were possible.
Where you perceive that the economy is overpowered, it is actually the combination of population and (exponential) manufacturing that is overpowered (and this has been shown in a number of threads). You get a lot of wealth because of a second bug, which you yourself already noted:
so from my understanding since economic stimulus does not grant 'income' but instead a separate bonus it should not be effected by the economic rings in the starbase.
Your understanding should be correct, but a bug treats the generated wealth from "Economic Stimulus" as income.
So if both bugs ("Star base economic module" bug, "Economic Stimulus income" bug) would be fixed the actual wealth generated would be: 18392 + 230 - 122.7 = 18499.3. Which is still a tidy sum, but it is the result of the combination of population and manufacturing and not of economics. Case in point: your economic income (in the last screen shot) is actually zero; An income of 0 increased by 285% (not 460%) is still zero.
i haven't looked into research yet but i would assume its along similar lines
The conversion ratio manufacturing to wealth is the same as the ratio manufacturing to research. The main difference between wealth and research conversion is: there is no "Star base research module" bug. And these observations, and the actually conversion numbers, can be found (spread out over) various other threads.
Personally i don't believe an economic boost by 285% in the end game is overpowered. In this case the perceived overpoweredness (a word of my own warped mind) of the economics is simply the result of an underlying cause and two bugs. And both of these bugs have been around since the alpha versions.
The really amazing thing is that both bugs can be easily fixed - i have done so on my own installation.