Polar coordinate transformation with code example here: Can we start with the circle equation as decision boundary? - #12 by Christian_Simonis
Please have a look! Basically it’s exploiting the information in the Euclidean, radial distance which has good predictive abilities combined with a linear classifier for this specific problem.
True! You can for example calculate feature importance as described with a code example in the repo on CRISP-DM.
I would suggest to read carefully through the provided sources that should support you along your learning journey, @mehmet_baki_deniz!
Hope they help.
Best regards
Christian