Regarding molten salt, I assume you refer to the liquid fluorine molten salt proposals. I looked into this too but it does create a lot more complexity in separation of neutron poisons from the molten stream. I agree that in an accident the design looks better and the fact that it has self regulating qualities is good. However, the molten salt reactors don't get around the largest issue with fission power, expensive to handle waste products. Reprocessing doesn't reduce the volume of waste much (only helps to reuse the plutonium and also reduces mining to some degree).
The story of the nuclear fuel cycle was of clean energy but it has left is with quite a number of very polluted sites and a huge bill in dealing with the waste sitting in casks and pools.
Perhaps fast neutron burner reactors could help (molten lead looks particularly interesting) but I think that with increasing political instability and the track record of humans being poor managers of super complex systems, nuclear may just not be out friend for a couple more generations.
Solar is quite capable of providing is with the energy we need (yes, base load too if we use another type of molten-salt!) and it's not prone to catastrophic failure.