Washington: Soil for large cedar planter?

Hello All,
I have built a large (8' long x 3' wide x 2.5' tall) outdoor cedar planter that I thought would be good home for low-maintenance, year-round interest plants like Golden Sword Yucca, Golden Creeping Jenny, Heartleaf Bergenia, Variegated Redtwig Dogwood, Heucheras, and Fuldaglut Sedum. Plants will be Northwest facing, have late-afternoon direct but mostly partial sun, and exposure to the elements.

Picture of the container below.

Couple of questions:
- what do you think of my choices of plants for our NW Washington State (Maple Falls area) property?
- what soil mixture would be best?

One more thing, for drainage rocks at the bottom of the planter, I have some limestone mixture left over from another project. Would this hurt the plants?

Any of suggestions would be helpful.

Thanks!!