You can install an underfloor heating system which is a series of pipes running under the floor where hot water runs and creates a warm floor and also heats the room with radiant heat. This is actually the most effective form of heating a space and is the most comfortable. The system components can be purchased or you can have a licensed contractor install it for you. You can put just about any type of flooring over the top......tile, laminate wood,........ Regarding flooring, if it is a very wet bathroom, I would prefer tile, but if will not get a lot of moisture you can use wood or laminate flooring.

I agree with divadeva. More lights. If you can add pot lights do it. If they're already there add task lighting and up the wattage on the bulbs on the pot lights (replace with LED and you can make them brighter because the wattage on LED is lower for brighter light). If you have all of that add decorative lighting. If ventilation is an issue find a way to move the air around or add air filtration. Maybe the HVAC is deficient. Maybe you can add a HEPA filter instead of the standard one that comes with the unit. Call an HVAC specialist to see if there is a way to boost air flow in the room.

You can use natural stone like marble for floor but do not use granite for floor at all as it is very slippery when wet. As for tiles do not go for glazed vitrified tiles for the floor for the same reason. ( floor becomes slippery once wet and may cause mishap) Go for ceramic anti skid tiles that are specially meant for bathroom floor. For wall tiles you can use whatever you like and then decide over the matching anti skid floor tile/ marble. Double charged vitrified tiles are usually used for flooring in rest of the house.

Send the measurement layout and the requirement details and we can work accordingly.