Considering I initially wrote that I don't really want to install OS/2, oh well... I now installed it like five times?
Even with DanisIDE, Warp 4 doesn't seem to like boot partitions that are larger than 2GB - it does install, but the entire partition table got thrashed twice... Also I chose the default install once, and then it ends up as FAT formatted instead of HPFS...
So anyway, I now have an 533 MHz Via EPIA Mini-ITX system with Warp 4 in english, there's a network driver (the chipset brings basically a Via Rhine II 10/100mbit), but I ran out of time for reinstalling the Fixpack and the Scitech display driver, and also none of the OS/2 Soundblaster drivers seem to like Via's SB emulation... But there's also an AC97 option, and I've seen drivers for that.