"would like to see this thing be the success that we hopefully all hope it should be, but the 'B'??. "
The B is irreplaceable. Who would have thought there would ever be a successor to the Harrier? Evolving it will be the only practical solution to the many worlds navies that will eventually use it.
"Will it be even possible to do anything similar to this extremely complex, eye wateringly expensive aircraft?"
Until its in full production and in service we won't know the true cost of it. But its much cheaper than the F-22.