See answers to bold above:
1) Majority of the top end Russian and Chinese jets are further advanced derivatives of the SU family.....including the PAKFA!!
2) The JFT is actually a 4th Gen platform. There is no doubt about it. But under the Chinese military's focus, they need the low-mid tier aircraft to have higher range and payload capability. China's landmass is huge and a JFT flying from one end to another, would require refuel like 4 times.
Its a great plane for the Indo-Pak theater due to borders being next to each other. About 90% of the air-wars in the Indo-Pak scenario, will be fought within 800 KM, where the JFT comes into play and provides a much cheaper bang for the buck.
But in China's case, a much larger geography and area coverage is required, way beyond Pakistan and India's situation. The J-10, J-11's are a much nicer option due to their larger payloads and range. The J-10 will replace the J-8, J-7 and the Q series, from what I am observing about the Chinese military. The future of the Chinese air force would be low-hi in the form of J-10 and J11 with Stealth options low - hi in the shape of the J-31 and J-20