The six-level test becomes nine bands in three stages — Elementary (1–3), Intermediate (4–6) and Advanced (7–9) — speaking and writing become compulsory at every level, and the top-end vocabulary roughly doubles.

Yes, at every band. In HSK 2.0 the written exam and the HSKK speaking exam were separate, so you could pass HSK 4 without recording your voice. HSK 3.0 bundles listening, reading, speaking and writing into one exam.

Band 1 includes around 500 words against HSK 2.0 Level 1's 150, Band 2 sits around 772 cumulative, Band 6 is around 5,500, and Bands 7–9 push the active vocabulary to roughly 11,000.

It depends on when you test and why. Testing within 6 to 12 months and most centres are still running HSK 2.0, so switch only if yours has already moved. Testing in 2027 or later, start on the 3.0 syllabus, especially speaking and writing.