I've never dealt with slugs or pill bugs when I lived in Z5 in amounts significant enough to have this issue, so was hesitant to suggest particular plants. Planting under a tree in general though, let the large roots dictate where you can/can't dig, and smaller plants require smaller holes. Takes longer to fill-in, but easier on the tree and plant to adjust to that, IME gardening under trees.
Some shade plants I've always liked, if they are pill bug or slug-magnets, I hope someone else can point that out...
Thalictrum
variegated Brunnera
Myosotis
Pulmonaria
Lamium
Trillium
Phlox divaricata
Aquilegia
Bergenia
Anchusa
bluebells
Hellebores
Artemesia
Alchemilla
Dicentra
Heuchera
Shrubs are more my thing, like beautyberry (Callicarpa americana,) Hydrangea, Pieris.
I miss bagged curb leaves! That's not the way it's done here. If you keep 'mulching' the lawn with clippings, mulching the bed with periodic applications of leaves, mulch, compost, the moisture loss will be much less in dry times, and drain/penetrate much more easily in times of too much, both in the bed and lawn although lawns by nature are lifeless (at the microscopic level) seas of dry, barren soil/clay/sand, with little or no organic matter.
In the bed, some supplemental water may be needed the first year as plants establish. Water as little as possible to keep plants alive, so the roots are forced to find their way to water as much as they can, and too much moisture can kill many plants as surely as too little. I LOVE the idea of doing that vicariously through potted plants, Chelle! A 2-birds/1-stone thing. Potted plants in shade are much easier to maintain than those baking in the sun. I've about given up on those and I LIKE to water plants.
Most folks don't let such wild things as these Ipomoeas and others grow in a tended garden, but I spotted this pretty beautyberry bush in the wild last week. A native, and birds love those pretty berries (as well as the other, native plants. They're just a bit too exuberant about spreading for most gardeners' patience level.)
