I would really appreciate some advice since I'm no pro when it comes to garden design. We built six months ago and we are just now getting around to the front foundation bed. I've just purchased some plants today (can take back though if I need to) but I am just not sure of placement or whether what I chose will work. I uploaded a picture of our house that was taken in November 2013 when just built. I can take another tomorrow if needed. The area I'm looking to plant in is to the right of the porch, under the windows. I'm looking at an area of 13x8ish which will bring the width of the bed flush to the porch but could also make it wider if needed. Also, I want to extend it past the right edge of the house in order to create a circle where I can plant a specimen tree (crabapple or dogwood maybe?).

Here's what I currently have to work with:

1 cranberry viburnum (back corner by porch?)
3 danica arborvitae (across the front?)
2 Red Satin Coreopsis (not sure where to place)
1 Mercury Rising Coreopsis (thought it was Red Satin and grabbed it accidentally)
2 Bonfire Surge (in between the danica?)

Also considering:

1 Yellow Azalea under the window
1 Potentilla under the window (or anotherAzalea?)
1 Ninebark Diablo (back right corner of house)
And maybe fill in the front corners with some of the following : Catmint, Echinacea (yellow), Heart Attack Sweet William

Thoughts? Are my placement ideas way off? Should I think about different plant options? I'm trying to stick with a maroon, purple, and yellow color scheme with some white thrown in as well.

THANK YOU for any advice!