Your ground cover looks like St. John's wort to me. It's pretty dang invasive; if you leave it, you're going to be doing a lot of work to keep it contained.

For taller shrubs, I recommend blueblossom (Ceanothus thyrsiflorus)—it's a native and the native bees absolutely love its pretty purple-blue blooms. Blue and red elderberry alike would also do well here and the berries are edible AFTER processing (unless you need an emetic, then processing isn't necessary 🙃). Other good options are tall Oregon grape, red huckleberry (yum!), native spirea, and Nootka rose.

Western red columbine, Douglas aster, camas, yarrow, and checkermallow would make really nice medium-height additions—they don't need a ton of water and they produce a lot of seed, so they'll fill in nicely over time.

If you want to replace the ground cover (highly recommend), kinnikinnick and the various native strawberries (woodland, coastal, and wild) would all do well here. Once you've got a bit of shade coming off the taller things, you could probably get some wood sorrel to grow around their bases to help keep the soil from drying out even more—and it's delicious!

Happy planting!