Redbuds cast a great deal of shade and often make it impossible to garden under them for that reason. They don't get too tall, but their branches will eventually strike the house at the distance you are contemplating. Serviceberry has the nice drooping florets and later the delicious berries that many birds love, so you could observe them feasting on them close up if a window looks out on that spot. It does well in partial shade and seems fairly adaptable; I see no reason why you couldn't keep it in shrub form if you are able to find one trained that way. However, I had some revert to small-tree form when I failed to keep them clipped, so you may be able to find a more trouble-free shrub for next to your house, and save your serviceberry planting for along your driveway or other opening from the woodsy areas. Pieris Japonica comes in many forms these days and is an interesting shrub that grows fairly slowly, so requires little attention. Some of the larger Rhododendrons would also do well in that spot, and the color choices and flower forms are wonderful. Of course Forsythia would also grow there, and there are several size choices. Witch Hazel is often difficult to get established, especially if it is a graft. It has a wonderful fragrance when the tiny flowers appear, but it grows very slowly and takes a long time to fill out, in my experience. If you don't mind thorns you could try Bitter Orange, but eventually it will probably crave more sun. The flowers have a nice fragrance and it has beautiful dark shiny leaves...but it also grows quite slowly. The hazelnut tree or shrub is not often thought of but is worth checking into. There is probably not enough sun for a lilac but the hibiscus can tolerate more shade and has flower choices that range from white to a soft pink to a lovely lavender color. All that said, Viburnums are available in many kinds, and the viburnum in any form makes a good wood that stands up to abuse quite well; they are one of the sturdiest shrubs out there, imo, unlike the hydrangeas, which make a very soft stem. However, oak leaf hydrangeas are capable of eventually getting fairly large, and have the interestingly shaped leaves and flower clusters. I believe their color change in fall is also attractive, and they do quite well in partial shade. Here is a link that might be useful: Pieris Japonica references

What Sunset Climate Zone? You can find this on the Sunset Publishing web site or in the Sunset Western Garden Book. When this is known is is possible to be much more accurate in determining what trees might like the climate there than with the USDA Hardiness Zones. Will the new trees be in the way when the alders are to be removed later? What if the alders start to break up before you get to taking them out? I had a bigleaf maple drop a limb on an established magnolia, cleft it right down the center. It did not re-sprout.

If you want to cut it down, cut it off at ground level and immediately paint the stump with some kind of brush/tree herbicide with 2,4-D in it. If it resprouts, girdle the new shoot and again paint the 2,4-D containing herbicide on it. Always use chemicals wisely and follow label directions. That stuff will kill other trees/shrubs if you get it on them. On the other hand, if you trim them up, they make a dandy tree in far west Texas where other trees won't make it. I don't think 9-10 feet from the foundation is close enough to hurt. I've had them closer than that.

I have seen several Eastern Red Cedar planted within 6' of a house and do ok. They tend to lead slightly away from the house and do not have large limbs or roots for 60+ yrs generally. Have also seen a couple of Arizona Cypress used successfully with similar results. Another possibility would be Italian Cypress. They are often planted within 3' of a structure seemingly without problems. The wild version has a cone shape in lieu of the pencil shape commonly seen. These 3 can take heat and drought and full sun. Personally it is against my religion to plant trees closer than 18' to a house. But from what I have seen used successfully, medium size conifers are what seem to work. California has some native cypress species that might also work well in this application. Would stay away from pines, redwoods, and other conifers that tend to get extremely tall/big.