Generally, our rule is: If the contractor is installing a concrete or plaster pool, follow his directions or risk voiding the warranty--because the walls have to cure. But unless the vinyl liner's warranty rests on following the installer's directions for maintaining the water, I'd take JimK's advice and ask what they are putting in--and charging you for!
You don't want calcium. Calcium is useless for vinyl liners but people add it anyway. It's solely to prevent the breakdown of plaster or concrete walls.
You don't want ANY algaecide EXCEPT possibly 60% Polyquat...nothing else, especially not ammonia or copper-based algaecide.
You don't want "Nature II" or any other "natural" system that promises to cut back on your chlorine usage (Except for an SWCG--Salt Water Chlorine Generator).
You don't want "Phosphate Remover" because with new water you won't have phosphates.