Welcome, Jan. First of all, to start out with a Polaris as your first JLC is awesome! What a great beginning.
I think the rotor sound is normal, but perhaps someone with more technical knowledge than I can offer more information. I have a few JLCs, all automatic, and I can hear the rotor in each one. I find the sound to be one of the charms of the watches, but to each his own. I am pretty sure tht the watch cannot be converted to a manual wind, at least I cannot imagine that JLC would do it; and even if it were possible, I would not recommend altering the watch in such a way.
Hopefully, you will get used to the sound of the rotor as well as the alarm rattle if part of what you are hearing is that.
Congratulations on getting such an amazing watch and I hope we'll see more of you on this forum. Please post a photo of your Pola on the Forum and particualrly in the Polaris Roll Cal if you have not already done so.
Again, welcome!
respo