I have only one thing to say about the lavender:
Plants, even container plants, are like a small earth. Bugs, disease, disease to the bugs, disease to the disease, mold, spores, seeds, anything can be smuggled in with another plant.
So whenever you decide to mingle your plants, make sure they are both sterile.
As in: DO NOT TAKE PLANTS FROM OUTDOORS TO YOUR GROW ROOM.
and; DO NOT CUT YOUR PLANTS WITH OUTDOOR TOOLS.
Besides that, I love your all natural idea for odor.
Oh my GOD I'm in LOVE with your plants.
That is the most beautiful case of flushing/nute deficiency in leaves I have ever seen!