A
o-
O - . He is rhesus negative
Any diet that goes well with a regular human being should do; your bloodgroup has no effect on anything except for which bloodgroup you are.
b+
Yes, each parent has all of the genetic components to produce an AB child, in this instance the A bloodgroup of the father and the B bloodgroup of the mother and, they both are Rh positive .
Means the red cells bear the K-Antigen, which belongs to the Kell bloodgroup
Yes, "O pos" means bloodgroup O, Rhesus(D) positiv
No, giving both the same gift puts them on the same level. Your wife will feel as if she is only like an asexual "mother" to you not a wife. Gifts should be personal and not come in a bundle.
Same as his wife's
Your wife's brother is your brother-in-law. Your brother-in-law's wife is not related to you, and the same applies to her sister.
Sister-in-law. same as your brother's wife.