Does the Portugal digital nomad visa lead to citizenship, and how is it taxed?

Yes, the D8 visa can lead to permanent residency and, eventually, citizenship. Historically, citizenship requires five years of legal residence, but the rules are under review, so confirm with official sources. On taxes, if you become a Portuguese tax resident (usually after 183 days), your worldwide income may be taxed in Portugal, though special regimes may apply. Seek professional tax advice for your situation.