SR The new tile floor is down. We thought about electric radiant but did not have room (old house and had constraints). The kitchen is completed but we do have some space in a wall that is an enclosure that had been built to house a built-in refrigerator.

So many questions. You really need to provide more info. Most of the time electric radiant mats do not heat the room, they take the chill off of the tile floor. Using electric mats to heat the room is pretty expensive unless you are in the tropics. So in the vast majority of situations, you will need forced air vents in the bathroom. But hey maybe you live in So Florida or have free electricity.

how many sq. feet is this home going to be? Sounds more like a palace.

Radiators do not dry the air any more than any other heat source. All other things being equal, the only things that affect the final relative humidity are the absolute humidity in the air and the air temperature. What makes indoor air dry in winter is excessive air exchange with outdoor air. The moisture that is produced by ordinary living (breathing, cooking, bathing and cleaning) leaks out. Poorly designed and installed ducted, forced air, heat can make matters worse by inducing pressure differentials turning the forced air system into a power vent. If you have excessively dry air, put money into air sealing your structure. It will pay off handsomely in summer and winter. Steam heat radiators that are installed well in a good design and maintained properly can be silent, or nearly so. There is something wrong with your system. I am not saying that you can easily fix it, but there is something wrong. A competent steam contractor will know how to add a steam heat exchanger to your current cooling duct set-up. High temperature steam is ideal for a relatively compact heat exchanger. The main problems might be how to run the pipes and if there is room for the heat exchanger. You may not be able to move enough air to heat even though you can move enough in the current ducts to cool sufficiently. It may not be practical for those considerations. If cost is no object, you might be able to add radiant heat to the floors via a steam to water heat exchanger with an associated circulator pump and expansion tank. You may be able to find a contractor on a forum that has a lot of "steam heads" posting. Try heatinghelp.com and terry love.com.