Judaism and Christianity are different religions with different worldviews.
One of the prerequisites to be Christian (other than ‘culturally’) is the ‘a priori’ acceptance of the New Testament. Christians have internecine wars over their own differing traditions about what the New Testament means or intends, and they’re all right. Each one does contraindicate the other.
Yes, absolutely. They are in a complex relation one to the other, not reducible to Christianity being a development of, or a successor to, or a denial of, -- Judaism.
Christians have internecine wars over their own differing traditions about what the New Testament means or intends, and they’re all right.
No, they cannot be all right, although they all, so long as they are basically Christian got something right. To you, -- I presume you are not Christian, -- these disagreements may seem silly or intractable, and of course you would be right calling them irrelevant as to you, they are.