Here is my version of preinit that at least start to boot from card:
http://sr.uz/tmp/preinit
I constantly change it (vi on the devise saves me). So the most useful from it right now would be the list of kernel modules in the right order to load and some ideas on what to do with mounted parts of file system (described in the first post). There is no debug output in it because I moved one to startup scripts. I was saving dmesg output and monitoring devises here.

I've compiled it in the FREMANTLE_ARMEL target with no additional options and outside the scratchbox with ARCH and CROSS_COMPILE options defined. The results were the same. With default settings produced kernel works fine (it even worked when I disabled some debug options). By the whay “make ARCH=arm CROSS_COMPILE=/scratchbox/compilers/cs
2007q3-glibc2.5-arm7/bin/arm-none-linux-gnueabi- menuconfig” only worked outside the scratchbox. I will try my luck compiling the kernel tomorrow.

ps. At least for now I managed to move /usr to the card