Lots of examples in this thread for "heavily planted." When the plants you
@imw have (photos in post #4) show growth, which they will when they have settled and adjusted to your tank conditions, it will qualify as adequately planted, and like someone else said, "heavily" is not really the operative word, so I am saying this is much the same here. There are fast growing plants in the tank. Floating plants are ideal as they are usually the fastest growing of all of them, and do a tremendous job.
I wouldn't worry about the wood toxin, I think you have done what was needed for that. I know it is not easy to "vacuum" into the sand substrate, but do what you can. The Python gadget connected to the faucet I find is a slower draining mechanism that the manual models, and I can actually dig down into the sand in my tanks if needed with the Python without sucking out all the sand. Takes a bit of practice.