Your text is very clear to me, Miniuki.
Rebecca comes from hebrew "Rivká: lace", literally "slip knot", from "rabak: to tie". The name refers to the firmness of the marriage liaison. In other sense, the meaning of "beautiful, sensual, desirable" for
Rebecca, is associated with the image of animals tied and "well-fed", ready for sacrifice. Anyway, in matter of names origin -I'm sure you know- no one can be absolutely right.
Hope this is clarifying