Sorry about having to remove your driftwood. It was really nice looking. Maybe there is some way to sterilize it - by boiling, perhaps? I don't know what warning you are referring to, so this may not be a good idea. Just a thought.
Another thought, totally unrelated to the driftwood - I personally wouldn't put bettas in a tank with your skulls, because their fins could get caught and tear on the teeth and other pointy parts. Probably more of a consideration with male bettas, but some of the females might have long enough fins for it to be an issue, too. Also, you'll need more places to hide for a betta sorority tank.
Also, you talked about a "heavily planted tank" and not needing to cycle due to that. Your tank doesn't look to me like it's heavily planted, especially if you had to take out the Java Fern
. Of course, you may be planning to add more plants. Seems like Byron said something about 70% or more planted in his response to my earlier post about still needing to cycle a tank in spite of plants.
Good luck with your tank. I'm looking forward to more photos as you get everything settled and get your fish.