I'm sorry, I missed your reply. :-( We live in north central Texas-- expansive clay soil, water foundations to keep slab from cracking, the soil can go from drought to waterlogged and back in days.

We’re neighbors! :) Some ideas if the bed can’t be expanded (it’s hard to say not seeing more, but I’ll try) … Dwarf Firepower Nandina. I love them. They might not get as red as normal in full shade, but are still nice hardy little evergreen shrubs. Dwarf Abelias — there’s one I can’t think of the name, but it stays quite small. Abelias are the best, my favorites. Wood Ferns. They’d love your conditions! But … they do die back in winter. Still, so lush and beautiful all summer. Variegated Monkey Grass. Keep the Yaupons, being patient, but knowing they’ll eventually outgrow the border. You might already have one I’m not seeing, but a bird bath might be nice in the area between the windows. Plants would grow around it, and it would give some height and interest (and make birds happy). You could plant some pretty flowering annuals, such as Impatiens, and others for an interesting mix. Or, a small concrete bench. I have one in between two of my windows, with a potted plant on it (usually Mandevilla) and pretty river rocks underneath. Internet pic, not mine: There are certainly other options than these, but again, it’s just hard to say not seeing more of the whole yard, and working with such a narrow bed. If the bed could be expanded, there would be lots more options. Our summers are getting more and more brutal … I’m finding my usual sun-loving plants are appreciating more shade now (not Lantana, those things are unbelievably tough).

If you ended up doing some sort of covering like stone or brick, you'd want to install metal lathe (I think) and that would give the mortor / stucco something to grip. Again - I suspect paint, hardscaping and landscaping will get you what you want and you'll ultimately forget about it. Get someone GOOD with landscaping, don't scrimp on the stairs, porch, etc - it will draw the eye.

Zero way of knowing from the limited info provided, and unfortunately it is not really a question that can be answered over the internet. I would say it has zero to do with encapsulating your crawl space and more than likely if something moving. As far as settling, how old if the home?