How long in days does take for the whole clutch to hatch.

Could someone tell me if a blue tit lays eight eggs in consecutive days, then fifteen days later, the first two hatch. Twenty four hours later, another three hatch but thirty six hours later, the other three are still being incubated by the female. In the mean time, the five chicks are being fed by both parents. What will happen to the eggs if they are infertile. Would she know and if so, what would she do with them and what will happen to the five live chicks. I don't like watching the little bare bugs being trodden on.
Would removing the eggs myself help or is there still a possibility of the eggs hatching.