Yes
fathers blood group and moms blood group determine child blood group. If a mother is O+ and the baby is A-, the father could have been type AB or type A, and could have positive or negative.
Yes
yes
Yes, the baby can be O+, it should be noted though if the mother also carries the trait for a negative Rh factor the baby clould also be O-.
can an o positive and an o negative make an a positive baby
No, they cannot.
Nope, the baby will be O positive as well.
of course, yes.
No. Two negatives can't make a positive.
No. There's a small chance the baby will be O negative--if both parents have an Rh negative (recessive) allele, and the baby inherits this allele from both parents, the baby would be Rh negative. But if the baby inherits the Rh positive allele from either parent, the baby will be Rh positive.
A person with A positive blood may be a carrier for O negative blood. If the other parent is also a carrier of those traits, the baby could be O negative.
no
No, they cannot.