Others can address your questions. What I'd like to suggest is that you tie that bed into a narrow edging that runs along the walkway. Unify it as one and it won't appear to be isolated. I think you'll like it better.

Remove your ferns and include them in the new design. Email me separately and I'll sketch something out for you.

I'm in zone 8 and don't know the plants for your zone. Our soil is alkaline and yours could be acidic. So, I'm probably don't have a lot to offer there.

Xtal

Hooked, being there, you are in the best position to determine if there is sufficient drainage currently. As long as you only plant and not change the grade, the drainage will remain as it is. (However, in the photo, it appears as if water may be draining toward the house. It's definitely not draining away for the ideal minimum 10'.)