I cannot see the front of the house, is plain siding without any openings?). Also I cannot read some of the handwriting identifying the plants on the landscape plan. The house is gorgeous & unique. Words that come to mind are sleek, modern, gray, smooth, unusual roof line, straight lines, rectangular, & prominent roof.

I'd repeat the gray siding and roof with gray rock mulch. Mulch the entire right front area. Thick weed cloth first, then large round river stone (not too small). These will add roundness and roughness & repeat the gray. I would have only the crab apple and rock mulch on that side. See

In the front the shrubs and plantings should look good 365 days a year, so I would not plant the Russian Sage, Roses, nor Hydrangeas in the front (plant in the back).

On the other side I'd have only boxwood planted (or some other similar shrub) all along that area with wood mulch.

On step to front door I'd remove the pot & flowers and have an urn in same color as front door. See:

Where are you located? From the plants you've selected I'm guessing that you are in a cold climate.

Overall I think you have a fairly colourful selection of plants. They aren't quite as contemporary as the architecture of your home but if you are hoping to soften the look then they may be just what you need.

I would suggest caution in putting roses near the path, in my experience they always want to send out a few long branches in late summer and the thorns will catch on people walking by. If you are going to use a rock mulch you will need a good quality fabric under the stone and I would suggest investing in a leaf blower and cleaning out leaves, grass clippings etc. every month or two so they don't accumulate and act as compost for germinating weed seeds on top of the fabric.

Crab apples can be a difficult combination with stone mulch since the apples can collect between the stones so if you are including one look for a variety that has very small fruit that don't drop before they dry, something like 'Malus sargentii' .

The Cistena Plums can be pest prone in some areas so it is worth checking with a local nursery to see if that is the case in your area. If it is some other options for purple leaved shrubs would be a purple barberry (possibly Rose Glow) Wine and Roses Weigela or, if you have the space, a purple smoke bush. The viburnum may also be problematic, (here in Ottawa they are often severely damaged by Viburnum Beetle) and you might want to consider using another plant in its place.

Overall it looks to me like you have chosen plants which are fairly low maintenance and will provide you with some blooms through the spring. If that's your plan I think you are on the right track.

If you are thinking of mulching the gardens with stones because you like how it looks I would recommend rounded stones, usually sold as 'river stones' or 'river wash' rather than a quarried stone which has been crushed since crushed stones have textured surfaces which collect dirt and tend to look untidy after a couple of years.

If you were thinking about using stone because it would be less maintenance than a bark mulch, in my experience stones over fabric are usually more work in the long run since you have to clean out anything that collects in them rather than just topping them up like you can with bark mulch. If you do you use a bark mulch I would skip the fabric since it doesn't really reduce the weed growth if you have about 3" of mulch and any weeds which do grow usually root right into the fabric, making them harder to pull up.

Have fun with your new garden!