Now that our mutual admiration society is complete, let me too add a few observations:
2. Alice Weidel herself will probably not become the prime minister because the party itself is still a few cycles away from taking over the parliament. But I think the takeover is inevitable not just because of the issue of immigration but for all of the other issues that the AFD advances - all of them duplicates of Trump's policies, including policies on energy, industrial policy as well as immigration.
Your observation that, "centrist-right CDU/CSU will plagiarize the AfD on important points", is very much on point and is perfectly in keeping with our American two-party system which, amoeba like, seeks to absorb popular upstarts. This is essentially what nearly happened yesterday when the CDU made common cause with the AFD and then broke the deal.
So, either way under either a label, I think we'll see Germany moving toward a populist right governance which is to be monitored closely, not because it is dangerously right wing, but because from an American point of view it is dangerously liable to associate with Russia and China.

More importantly to the US, such a Germany would be less likely to do our bidding.