I only have an hour tonite, to figure out what to actually do now with the dyld :)
At first I thought that it was merely a linker option to set a different dyld. But not so. So I will just read up on the MachORuntime and then call it a day.
My current theory is, that the dyld path is coming solely from /usr/lib/crt1.o. So I will try to find crt1.o in Darwin somewhere and link that against my dyld and see what happens.