I too would put the bead behind the hackle - if it must have a bead. It works the same as a tuft of dubbing there - although the bead probably should be smaller than pic 3. You can put a base of thread there and crazy glue the bead in place, or you can actually wrap thread on one side, do a half hitch and then just bring the thread to the other side. A single strand of thread is hardly noticed but locks the bead in place.
If you wrap the hook with lead, the traditional way to tell which are weighted and which are not is to use different coloured thread on one vs. the other. Sometimes the thread is read, but you could also use green or brown if it is for these 'nymphs'/spiders and you want a more natural look.