but were any cast on Samantha,and by whom?

By Endora in #77 "Witch's and warlocks are my favorite things" Chirp Chirp !!
and as well in #199 "Turn on the old charm" when for lending Darrin her Fathers magical amulet, Endora spells Samantha into the Mother of all Shrews much to Darrin's consternation.

Many times when Sam was sent back in time such as in #142 & #229 and #208.

That is just off the top of my head.

Larry Tate :)

but were any cast on Samantha,and by whom?

In episode #77,Larry Tate,you said that Maurice cast a spell on Samantha.You are right and wrong.It was Endora who turned Darrin(Dick York),Samantha,and Aunt Clara into birds.Maurice demanded that Endora,Hagatha and Enchantra turn them back to normal.THEY(Endora,Hagatha and Enchantra -not Maurice)did.And remember:Sometimes Samantha said "good"when Endora left.She never said "good"when Maurice popped out.