I think a good way to answer your questions is to review the ecology of
this organism. Venus-fly-traps are found in peat bogs and grow in full
sun. These suggests that high light intensities, high humidity, and an
acid soil mix are required.
1. You didn't say how far from your lights you are growing them. Try
six to eight inches and begin with a 12:12 (day:night) light regime to
begin with. Allow them to grow for at least two months to evaluate this.
2. Gro & Show bulbs are rich in reds and blues, which are the
predominant absorption bands for chlorophyll. These bulbs are adequate.
3. Yes! The poor response you are observing may have to do with
water/humidity. My growing experience has been with terrariums. I use
unmilled sphagnum moss and general use potting soil (3:1(v:v)) mix. Keep
the medium wet! Ventelate the terrarium if: 1. condensation is too
heavy, 2. Fungus growth is evident, and 3. if leaves of the
Venus-fly-traps start to blacken (bacterial contamination).
Let me know how it goes.