Well, I would have to agree that if you are moving in two years, you don't want to spend a lot of time or energy on a lot of landscaping. The new owner may not like what you did, and end up ripping it all out and starting over to suit their own taste. That said, I think I'd like to see a small ornamental tree in the area about halfway between the lamp post and house to break up and disguise that large expanse of brick and change of siding material to the left of the big window. Maybe Amelanchier, something not too dense. I'd also like to see something softening the edge of the retaining wall. Low growing Cotoneaster has interesting branch patterns and colorful berries in the fall and winter. Microbiota could cover that bank and provide year round color, or one of the low growing Junipers or other evergreens. That bank is your biggest problem, IMO. Rhododendrons and Azaleas are nice, but once they finish blooming in spring, they will just be foliage. Adding in an Oakleaf Hydrangea for summer flowers and fall color might be nice off to the right side. Unless you go with a Meyer Lilac or a mildew resistant cultivar, you may end up with a mass of powdery mildew for the rest of the summer. Not very attractive. Making the planting area near the house a little deeper to leave some space for a couple of clumps of perennials that bloom at different times of the season will give you some extra interest. Add them in masses, not just one or two, so that when they bloom, you actually can see them.

Another book to check out is The American Woodland Garden by Rick Darke. I live on a rather large acerage that was logged prior to our purchase of it, and I constantly do selective removal and planting, so I'll share a bit of my experience with this approach. I have 3 varieties of native viburnum and two of native dogwoods (including my favorite, Cornus alternifolia) that I leave and thin back the competition from, as well as some natives like rhodies, blueberries, Kalmia, and lots of ferns and wildflowers. I have added additional woodies like other rhodies and kousa dogwood, as well as natives that weren't already here like clethra, redbud, vernal witch hazel, and fringe tree. I also do removal of invasives like barberry, buckthorn, honeysuckle and autumn olive with a combination of pulling with a pair of oversized pliers for the smallest plants in the loosest soil or cutting small saplings with a saw blade on an industrial strength weed whacker-type implement or a chainsaw, depending on the size. The ones I cut often get some Roundup directly on the resprouts, avoiding nearby desirable plants. We have drilled large holes in the top of a few of the larger stumps and added a bit of fertilizer as the damp and extra nitrogen encourages the growth of bacteria to rot the stumps. A brushhog (large tractor-mounted mower) has been helpful in keeping back growth of undesirables until some of our preferred plants have gotten large enough to fend for themselves. (Often my plants are small in order afford more of them.) I also do use Roundup on the poison ivy in areas where I or the animals will be as I'm really sensitive to it, but again, I shield or avoid nearby desireable plants. I have acid, fast-draining silty soil with little organic matter, so I do mulch, but with quite light layers of shavings from my husband's woodshop that nestle down below the foliage of the native ground covers and spring ephermerals. It works rather like an addition to the natural fall of leaves and pine needles, and holds in moisture where it may help struggling native plants that need a bit more even moisture than my soil provides, and has worked quite well to prevent or reduce the sprouting of undesirable seeds of plants like blackberries. Although I have lots left to do, it gives me joy to see the number of flowering plants in my partially to deeply shaded woodlands throughout the spring and early summer. It sounds like much of what you've planned will thrive in your setting as long as you research preferred light levels for each individual variety and perhaps be ready to do a bit of moving around to make some plants happier. For instance I've found that Ilex verticillata really prefers a fair amount of light (close to full sun) to bloom/berry well and grow thickly. My Northern Hi-lights azalea is planted next to a Nova Zembla rhodie, which is supposed to take a fair amount of shade. The N. Hilight blooms prolifically every year, but the Nova Zembla is getting moved to at least 1/2 day sun, as it doesn't currently bloom. Just one other thought - if you leave some of your small hemlocks, the dark green, fine-textured foliage makes a lovely contrast/backdrop to blossoming trees and shrubs and variegated folage.

There are a number of causes for what is rather generically called "branch dieback." This commonly occurs and usually does not mean the entire plant is on its way out. The best thing you can do is prune back to green wood and make sure the rhododendron receives enough water and nutrients so it has a good chance of growing replacement branches. It may or may not be significant that the plant closest to the magnolia is the one suffering. One of the photos seems to show some discoloration of the magnolia leaves - possibly fungus. Your County Extension Service or a nursery with knowledgable people can probably help you a good deal more than long distance diagnosis.

Mad gallica and Bill, the last time I tested my soil was about 10 years ago and it was 6.0 at that time. I've already decided to do another soil test this year. We'll see if that has anything to do with it. Our neighbor across the street has a great Rhododendron in front of his house that is huge and blooms wonderfully, and he does absolutely nothing to that shrub. So, I'm not sure what the difference is. I have neighbors with five mature Silver Maples within 5 to 15 feet of my lot line on two sides and another neighbor with a London Plane, a White Pine and 7 Spruce trees within 5 to 10 feet of my lot line on another side. And I have a small 1/4 acre lot. We make our own compost and add it every year and spread a lot of bark mulch too, save neighbors leaves with our own and chop them up and mulch with those, use the sprinklers in dry spells. I just think the surrounding trees are sucking the moisture and the nutrients out of the soil. But, maybe the PH could be part of it. The azaleas that I've had the longest have grown and bloom every year and are in the front. My kids gave me 'Girard's Fuchsia' azaleas and a 'Nova Zembla' Rhody for Mother's day the last few years and I planted those in the back in the dripline of the Maples. They did bloom the first year, but they are looking like the leaves are sparse and not as vigorous. The Rhody lost foliage and has a number of bare stems. It has new growth around the base, though. They're just not thriving the way they should. Thanks for mentioning the PH....good idea.