Ok, so it works. I think it was mainly the mistake that fatalsaint caught; sure enough, the softlinks that I had made were pointing to non-existent files. However, I also simply copied the libflashplayer.so to the /usr/lib folder (instead of to /usr/lib/browser/plugins).

I think Iceweasel knew about /usr/lib/browser/plugins because it shares the /home/user/.mozilla folder with MicroB.

And ... what does libdude do? Is it anything like libsexy?