Qatar
Territorial: a resident's profit-share from a foreign prop firm is generally untaxed (foreign-source). The flat 10% only hits Qatar-source business income. Crypto doesn't change the source test.
Territorial system. Employment income never taxed; business income taxable only if Qatar-source. Foreign prop-firm payouts are generally outside the net.
0% on salaries. Qatar-source business income: flat 10%. Foreign-source contractor income: effectively 0%.
Social insurance applies to Qatari/GCC nationals only; no self-employment levy on foreign contractors.
Only those with business income generally file (by 30 April to the GTA). A non-incorporated freelancer with foreign-source income typically pays no personal tax.
No special personal crypto tax; what matters is whether income is Qatar-source.