To be honest, I would love to see the PLAAF requesting a very long range bomber. With 4 WS-15s, an aircraft with 260 tons of MTOW is possible. Such an aircraft can have 110 tons of empty weight, 30-35 tons of payload and the rest would be the fuel. This distribution (40-42% empty weight, 14% payload, 42-46% fuel) is very common among the current large long-range aircraft. This would enable around 7500 km round trip without refueling and it would also enable 12 heavy cruise missiles to be carried. The current cruise missiles of 2.5-ton class have a range of around 3500 km. This enables a 11000 km striking range. This is enough to hit Chicago from Beijing. The aircraft can also have the capability to carry fuel tanks in the bomb bay to further increase the range. With optional buddy tanking pods in the weapons bay, it would also make a terrific tanker with its high survivability. Just like the MQ-25 Stingray but oversized. With single refueling, it would be able to strike most cities of the USA from most airstrips of China. That is what would really deter the USA. The thought of a regiment of these bombers launching 196 CJ-10s to Washington DC or NYC is exactly what would make the war with China unthinkable to the USA. I don't know how close the H-20 will be to what I describe here. If it is using WS-10s, California is the furthest possible.The B-2 is capable of carrying fuel as part of its payload package, extending its range.
It'd be sensible for the H-20 to have extended range through modular internal fuel tanks if it's needed to strike targets like California, but have the bay capacity to increase its payload on hits vs American bases in Guam / Japan.
Not necessarily. You might wish to move ZTZ-99s (or any future successor) in an area where less stealthy transport platforms would have trouble. But that requires a substantial redesign, and the most realistically you could want to move would be supplies for ground forces.