Metric is about measurements, not formatting. The date measurement is in days, months, and years for both ISO 8601 and what’s shown.

External trade with capitalist cultures doesn’t mean the Federation itself has internal capitalism, it’s just a necessity for getting things from cultures outside of it. All the poker on the Enterprise was almost certainly just friendly games with chips, not actual gambling. Picard himself says money doesn’t exist so it’s not like they’re getting a salary. And I can’t recall the projects and patrons you’re referencing, but that could mean someone providing non-monetary support like using their connections or social status to support the project.

Is there capitalism within the Federation? There’s capitalism on Deep Space Nine for sure, but that’s an outpost at a merger of cultures and governments. Not sure if we have seen money from any Federation cultures. Individuals might have and use money to buy things in other cultures, but I’m not sure such things take place within the Federation itself.

At least in the DS9 episodes Section 31 was still an antagonist organization.