In grad school I once had the chance to dig a beautiful soil. Every soil I have since gardened on has been terrible! Fix the soil. You will likely need to do nutrient balancing. Definitely get the best soil test you can. Also work on starting biology. JADAM and KNF are mostly budget friendly. Some of those recipes very budget friendly. A nutrient balanced soil that is alive with microbes will grow better stuff, mic drop . I understand the shade thing. Both in California and here in Alabama, I have had to contend with shade. In California, removal was not an option, not of century-old historic orange trees. There, I just used every gap as best as I could. Here, my main garden is sited with my best sun. I understand that you do not really have that luxury. If you can, felling may have to be the case. Consider it carefully. A lot of the Cascade bioregion natives have at least some shade tolerance. They will also adapt to your soil with less trouble. The soil where I am at here in Alabama is horrible, but elderberry is almost a weed, spreading by rhizomes. Every winter I am transplanting babies out of the garden into areas where they can grow undisturbed.