How to determine the size of electrical service needed for a house.
2-heat pumps (with heat strips), 2-water heaters, 2-pool pumps, 2-electric ranges, 2-washers and dryers, along with all other lighting, etc requirements

You need to do a real load calculation. This is found in Art. 220 of the NEC.

Sorry, but the info given barely begins to help. Need to know first and foremost the sq/ft of the home. Also, if this is a 2-family or not.
Next, you need to know the size/amperage/wattage of all that equipment you list. Simply saying "heat pump with heat strip" tells nothing. Could be 5kW of heat, could be 25kW. BIG difference. Same goes for the outside unit, and the rest.

This is a complicated calculation, it is not something someone can just wing off the cuff.