Cocaine isn't actually all that unusual in its side-effects for heavy addicts. Sufficient "caffeine abuse" could do the same, though at least I get too high a tolerance for it to get more than buzzed. Heroin doesn't cause problems operating heavy machinery to most addicts. Why? Because they have a tolerance for it. Most smokers, including me at this point, don't have the smoking buzz. It just curbs anxiety and fulfills craving to light up. Most dosage spikes for cocaine are only really a strong stimulant effect not unlike drinking large amounts of coffee. It's only when it's ingested in crack or freebase form that it statistically induces psychosis. Or when somebody uses it to stay awake for two weeks straight. Otherwise flake or leaf cocaine is relatively safe, even if I dislike its emotional effect personally. And if heightened reflexes are in demand, people very well might do it for that. Studies on cocaine and amphetamine "intoxication" actually show people drive better on them, though the gov never quite manages to quote from them when it comes time for discussions of penalties for DUI. I would expect that effect, though, would be no different for people operating Ice Hammers or the like.
Oh, and the problem of addiction is about 70% solved. Ibogaine is almost a "silver bullet" for opiates. And it shows some decent effectiveness for other addictives, though it looks like they use a different "pathway" for addiction and so it only does something to the basic psychological addiction. What we'd need to research would be to find
why ibogaine works on opiates, and find a way to make it do the same on the various other stimulant and depressant addictions.
As to the likely intoxicants, it might actually be common to imbibe some THC if you're working long hours in an ice mine. It only somewhat impairs reflexes, retards soreness, and makes it a lot less dull to perform repetetive tasks involving hard focus. A number of hunter-gatherer societies that have marijuana available smoke it before they lay in ambush waiting for prey. Hallucinogens would require significant down-time to imbibe, my own experiences with them range from 6-12 hours for the trip, and usually crashing afterwards into sleep. Depending how good their air-reprocessors are, they may not like actually smoking things. Clogs the filters, as any smoker with central AC can attest to

But vaporization or alternate methods for ingestion are possible even so. The only issue that might crop up is many of these intoxicants come from plant sources that take specific climates or significant amounts of hydroponics production. Which just might ensure it's relatively expensive to produce any of them for a natural form, or an artificial form is produced.
But yeah, seems about right for free markets in currency. That also sounds like only a list of the major trading ones. For an ordinary person, Mrs. Guzman might've been willing to trade in an exotic currency. Minor ones might just be issued by a few people for goods or services they produce, sort of like gift certificates, heh. For Guy and Fiorella, I'm almost surprised she doesn't demand they pull the gold out of their fillings.
And Guy is still an asshole for tipping in a continental when he knew it was worthless. Both before and after Ceres' free market in them. What did he think he was doing, spreading the civility of toilet-paper currency one bill at a time?