It now boots fine just like that from USB CD/DVD drive on my ASUS EeeBox 202, and USB keyboard and USB mouse also works excellent now

Next step is to create bootable USB flash stick, and I have tried to do this simply by telling AROS Install to use usbscsi.device, correct unit, and then tell it to "wipe disk", but then it just says "disk is full". I also tred partitioning manually, and it all works (PC-MBR, PC-EBR (active), AROS RDB, DH0 SFS-LE (bootable,automount)), and survives reboot, but does not show up as DH0: anywhere (c:info). Probably some poseidon settings?