you got your heart in the right place but you idea won't work simply because value is not based on how much you make but in how much you need.
The problem with this is that no one really needs Credits, and Credits are so cheap to buy.
With the new donation method they're as easy to get now as they were at launch.
The main purpose of credits after you've got everything you need from the store is to sell them on the AH for gold. There's not very much you need in the store. You get snowflakes (as per your example), expansion scrolls, costumes if you want, stellar/solar/lunar farms, a tree house, uprgade your hauler, etc.
Everything after that is optional.
RNG boxes are nice for the charms, but we have in-game ways of getting archeum and points.
The only ongoing purchase from the marketplace that players need are tax certificates.
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Adding a gold sink will heavily boost the price of credits and will make it harder for non playing players to acquire cash items.
4.) 10% of credit buyers are forced to buy them because is way cheaper than acquire mundane items(like this I mentioned before) for gold.
So, if the team can remove number 4. and make those mundane item easily buyable with gold you can drop the value of credits by a decent amount, maybe 10 to 15%(remember you cannot buy exact amount of credits, so you ned up buying more credits than you need very often hence is always a bit more than the base reduction)
You're thinking outside the box, but there are some flaws with your ideas.
A gold sink would make the price per credit go down not up because there would be less gold in circulation.
Compare the server's economy now to the server's economy at launch,
at launch there was less gold in the game so you couldn't pay 2,000 gold per 1000 credits. It was more like 200 gold per 1000 credits.
The reason gold is so cheap is because there is so much of it.
You could argue that the credit price was cheaper because they were easier to buy back then, so there were more credits being sold, but that isn't true since credits are just as easy to buy now with the new pixel game card -> shadow card exchange.
Your example of Specialized Snowflakes is an OK example, but the problem using that as a benchmark is players are only ever going to need a finite amount of Specialized Snowflakes. Building Titles are a good example, but Taxes are even better. If Taxes were paid with in-game gold instead of credits it'd be a great way to get excess gold out of the game while serving a legitimate function. Unfortunately I still think players would rather craft their own taxes than buy them.