Synthesis of Ethyl 4-Aminobenzoate (benzocaine)

If too little sodium carbonate is added, the yield may be lowered. Why? (include a structure of the product as it would exist in a solution that is too acidic?

If too much sodium carbonate is added, the yield may be lowered. Why? (include an equation that would happen if the solution is too basic)

How does the removal of ethanol by distillation help to increase the yield of the product?