For perennial suggestions come on over to the New England gardening forum and post your question there. You'll need to say more about the direction the house faces/how much sun and shade it gets. Any other info (how tall/wide the plants should be? Do you want the flowers to bloom in spring? midsummer? fall? favorite colors? open to shrubs?) would help too. For annuals I'd just head over to your local garden center and see what they stock for your region. The garden center will have them divided by sun and shade annuals.

If you have the umbrella pine 10 ft from the house it is going to receive comparatively minimal benefit from its presence. And walls make wind worse, by compressing it - when the wind gets into where the walls are. Except where there are enough wall angles to have some effect on wind movement the main benefit of walls to plants is by providing added warmth from reflected heat, or cooling shadows. And to get in on this plants need to be against walls or similarly close. Later when it is sizing up the umbrella pine may seem too big to be even 10 ft. from the house. And to have gotten to that point it will have to have survived the wind and ice anyway - the house would only help with ice if it provided a long extended roof that the conifer was growing beneath.

I'd put a mix of low-growing flowering perennials under the Japanese Maple. Pink coreopsis, phlox subulata, veronica spicata, and salvias. Pick a mix of flowering times, so you have blooms all summer. What's in the bed to the left? No to tall plants flanking the entrance. Note that your two beds on either side of the walkway are not quite the same size. I'm fond of broadlead evergreens --- rhodos and azaleas. It looks like you have some yews to the left. If you are going to remove them, I'd plant the best ones on either side of your driveway near the road.

Foundation plantings typically focus on evergreens so if you do not mind bare sticks for much of the year, blueberries could work. Keep in mind that if you are interested in harvesting and eating the berries, you should pick at least several different varieties to maximize cropping and extending the harvest season. " I've read that new foundations make the surrounding soil alkaline. If sulfur is added at planting, is that enough to counteract that effect? " It is not just new foundations that create this issue - concrete will continue to leach lime over its entire lifetime, raising soil pH, so you would need to continue acidification of the area indefinitely.