"BTW. is this Icaros thing official base setup for AROS or rather like Chrysalis pack on MorphOS?"
The base are the nightly builds that are rather minimal and primitive, there is no "official setup" but the different preconfigured distributions. Chrysalis pack is a addon as I understand it installing additional software to the standard setup but the standard setup already perfectly working for its own. On "AROS" there is nothing that can be compared to the standard installation of MorphOS. It is propably more comparable to the Linux world with its kernel and the different distributions.