I always like the bad news first - the crepe myrtle is too close to the house and should be moved while it still can be. The boxwood will eventually outgrow it's little space, but that can take a hard pruning to keep it for a few years. The fallen leaves are okay. The silvery plants are Dusty Miller - and I think the snaps, plumbago, alyssum, and dianthus are fine. A nice change from the tortured into submission evergreens in some yards. Snaps will wilt when they need water; but they'll put out more bloom spikes if you pinch off the spent ones. Your conditions in zone 8 are much different than mine in zone 4 - we rarely get prolonged heat enough to bake a garden like you probably do in Houston. I wouldn't plant anything directly over the buried downspout extension - too easy to forget it's there and slice through it with a shovel or something. Some more snaps underneath the arrow, some more allysum on the up side of the dianthus and you're all set.

GREAT! Thanks so much. I had never seen these before and then found hundreds of them just a couple miles from home. I appreciate your help.

I'd go with weedwoman's id. Ragged Robin is a British native which likes damp situations. 'Jenny' is more double and fringed. It is definitely not a mint flower and the foliage behind doesn't belong to the flower anyway as the OP stated.

Petunia. If you are careful you could probably transplant it with some sort of soil around the roots. You can shade the plant from sun for the first few days after transplanting by placing a paper bag over it.