Seems to be working fine after the Network update. I was still not able to install the AmigaOS 4.1 FE Update 1 automatically, but I was able to download it from the member page at Hyperion.
Of course, PPC/AmigaOS 4 under emulation is still a bit rough around the edges. I experienced a few crashes and freezes, especially when browsing the web, but it works better than when I was trying to set everything up manually. The emulation now has 646 MB of available RAM, which I was never able to achieve myself (network and graphics started acting up at 384 MB for me). It also makes the confusing task of creating the system partition a lot easier (fully automatic).
A few nitpicks: The mouse wheel doesn't work, and 32-bit under WinUAE, Configuration, RTG, is set up wrong so you get pink icons in 32-bit mode. I changed it to A8R8G8B8 and it seems to work.