Has a certified arborist evaluated your large tree in the past few years? The portion showing in the photo shows multiple bare branches. Also, the wall around the tree suggests a possible grade change. Before spending time and money on shrubs, ensure that your tree doesn't need work. Tree work isn't as much fun as choosing flowers (actually it's no fun at all) but it needs to come first.

I'd remove the brick half-circle around the tree and put in a short 1.5' brick or rock wall along the entire sidewalk and front path sides of your left-hand yard. You can then do low-growing junipers or cottoneaster all along the edge of the grass and have things like thyme, phlox or creeping jenny filling in between them, creating an orderly mass. We did this in our similarly small city front yard and it's really pulled everything together.

Plenty of trees can withstand sdubstantial pruning. I'd have someone remove lower limbs so you don't have a mass of tree blocking the top of the house. Unless you love it. I have a huge tree out my bedroom window and it gives the bedroom a treehouse feel.

Celery, the visualization helps me so much, thank you!

I agree with giving the tree some attention- if it is viable long term I'd have it thinned/trimmed so it isn't enveloping the house. If it's not viable then get it out before you spend too much money planting underneath it.

The rendering photo is nice but I'd advise against those tiny patches of grass along the curb- why leave one square foot patches that have to be mowed?

And if your swale is city property be aware that they can come through and destroy it all if then need to replace sidewalks or water lines etc. So I'd skip the fancy blue spruces and stick with lower cost plants out there.

conifers are trees .. not really shrubs.. that means they keep growing for your lifetime ... they do not stay small round balls .. and in fact.. my picea pungens of ball sort is now 8 feet wide .. and that isnt going to work there in the future ...

z5 is half the US and wildly divergent ... zone is simply minimum low temp on the coldest day of winter ... it doesnt help us much ...

is the road plowed .. does snow accumulate there.. and are you willing to risk $200 dollar conifers only to die from road salt ... or plowed snow ...

i would stick with die to the ground perennials here.. if snow is a variable ....

and i would NEVER top or thin a tree ... either love it.. or remove it.. dont torture it .. imo ... every major wound you open is part of a death sentence .. but of course... that is in tree time.. which i counted in decades ... so you may be well dead by the time this all happens ... proper pruning is a different issue ...

and lastly.. what the heck is that guy doing who photobombed your pic .... crikey ... or are you just pretending you dont know him... lol ....

ken