Kosher, and a historical right

Hello Rabbi,
A. Has the Rabbi heard of the arguments that most of the poultry marketed today (natural “breeder” poultry) are a mixture of several species of poultry (with and without tradition) and therefore poultry should not be eaten today. They claim to strengthen their claim that there are several changes in roosters that can testify and indicate this. Has the Rabbi heard of this or something like that? If so, is there an answer? Are they wrong about the facts? I simply don’t understand it…
B. I saw somewhere that the rabbi says that we have a historical right to the Land of Israel because we were the first to be here (and exist today…), two questions: 1. How does the rabbi know that we are the first? I saw an argument from Palestinians that they were there before us, that they are Canaan, etc., supposedly a dispute in history, how does the rabbi know how to decide? 2. Let’s assume that it is ours, why are all the sales that were here invalid, a Jew sold to him who sold to him who sold to a Palestinian who today owns it, how do we have a right to that land?
third. Does the rabbi have or does the rabbi talk about this somewhere about a solution to the Israeli-Palestinian conflict? Two states? Expulsion? No solution?
Thank you in advance.