There is no need, in this day and age, for Darrin, or anyone else for that matter, to forbid sam from using magic. Whether she's a Stay at Home Mom, or whether she works at a school, the thing about Sam not using her powers is that, on very many levels, she's a rebel. Even more so than her otl series Kooky Sister.Or maybe she's just self-employed. Or an artist. One who creates beautiful works of art through magic. She marries a man who actually wants a trad-wife and forbids her from using magic to create her works and she must painfully learn to use her hands like humans.
By the way, I'm pretty sure they'll at most produce a pilot that won't go anywhere.
In this day and age, a witch not using her powers would be equivalent to someone baking their own bread as opposed to buying packaged bread at the grocery.
If anyone is keeping Sam from using her powers, it's Sam herself, and no one else, and all the drama comes from that.
Her family looks down on Darrin because he's a Mortal, like a lot of Wizards in Harry Potter look down on Muggles. Then, there's the issue of the daughter, Tabitha, who not only has to learn how to use her powers, but also how to do so in a way that won't harm the mortals, and also that she shouldn't use her magic whenever she feels like it.
Plenty of room for drama and problems there...