Good looking red betta. I wouldn't add the red cherry shrimp. I raise RCS for my lfs
and I have many bettas. The betta will either eat it, or the RCS will hide constantly. I've tried them together and I've even tried them with a smaller female betta. The shrimp were lunch. Betta have rather large mouths and shrimp are just super-yummy treats for just about any fish.
I would add some top cover. Bettas come from rice paddies and are most comfortable in densely planted, shallow waters with lots of top cover. If he's really comfortable you may even see a bubble nest. I have one betta that blows bubble nests, but he stops when I trim his plants, then starts again when his plants grow back. They don't care if the plants are real or not, top cover is just grand to them.
I wouldn't add anymore fish in a 5 gallon, but it didn't sound like you were going to. Cute little tank.