I believe I would be able to grow all these plants at my home in zone 9B. I hope to obtain them and try them out soon.
Comfrey – mulch plant, medicinal
Mashua- Vining nasturtium, edible leaves and flowers and tubers, natural insecticide
Buckwheat- mulch maker, edible, draws pollinators
Lamb’s Quarter- edible, nutrient accumulator, easy to grow
Sheep Sorrel- edible, easy to grow, nutrient accumulator
Yarrow- edible, attracts butterflies, nutrient accumulator
Fennel- attracts butterflies, edible
Plantain-edible, easy to grow, medicinal
Mallow- edible, pretty
Tree Kale- edible
Stinging Nettles- edible, soil builder
Holy Basil- edible, medicinal
Skullcap (Scutellaria galericulata)– easy to grow, medicinal, smokeable
pinellasnolawn 
I got some comfrey from Coe’s Comfrey in North Carolina. I have it growing in Tampa. It is in the shade with micro irrigation. Coe claims that it can grow in the sun in 120 degree heat but several very experienced local gardeners/permaculturists say it won’t grow here in the sunlight.
You’re definitely right on the comfrey. Mine does NOT like the sun here. I killed a half-dozen or so of them. The only ones thriving are either near my house or totally being coddled. There’s probably a better nutrient accumulator for this area – though I still grow comfrey for the health benefits.
My local herbalist, Willow, said to plant comfrey under an oak tree, mulch with oak leaves, crowd it with other plants, and pick the leaves frequently. I just planted one and it’s doing well. We’ll see how it does in the summer.
Hope they do well. Mine are happy right now and have grown a lot of new leaves in the cool weather… but I have a bad feeling about later. I’ve got oaks, so that’s something to try.
Dive deeper into the tropical stuff, too, and you’ll be happy. Cassava, cattley guava, okinawa spinach, dioscorea alata, papaya and pineapples on your south wall (if you have a spot), sugar cane, ti plant, moringa, etc. You’re in a great zone to experiment – a bit warmer than me. Good luck – and keep hacking at that lawn.