Yes, rake the needles (and gravel) onto the path, before improving the soil, and periodically during the off-season for the flowering plants. They tend to restrict growth and do not add to the appearance of the foliage or flowers, don't you agree? Not sure what does well in your area, but here's a list to take to your garden center that might brighten your day, and cover the ground. Cotoneaster dammeri, Juniperus conferta 'Blue Pacific", Euonymus fortunei 'Coloratus", Asperula odorata, Dianthus gratianopolitanus "Bath's Pink", Adiantum pedatum, Ophiopogon japonicus, Parthenocissus tricuspidata or quinquefolia (I forget which one climbs up the trees, but get the other one), Most of the above will do well in any pH soil, so don't be afraid to sweeten it, if advised to locally. I would not plant all these together, but you have plenty of room to match up good companions in each area. Some, like the junipers like a little more sun to make you smile. That should get you started in covering the ground. The local folks will be eager to sweeten the list, I am sure. Enjoy the process. Involve your family and friends. Nobody does it alone.

After staring at your pics a few times I think I've figured out what's bothering me. The garden bed sticks forward. If you need it for the size of plants in the ground it might work but if you're only going to have pots you can line the edge up with the wall of the house I think? What is the depth of the garden bed? Colour and placement of the pots. The pots look terracotta and the brickwork looks more reddish, is that right? It doesn't look like it goes together. Maybe you can use those pots somewhere else where they aren't right beside the brickwork and get some pots for that location which are either darker and match the trims of the house or are lighter and contrast with the house more. I think the pots need to somehow relate to the windows. If that room could use some privacy or shade you could put two pots in front of the windows. If you want to preserve the view out then you could put three pots against the brickwork. The mulch. It looks too low for the edging. (What is the edging?) The colour, like with the pots, doesn't look like it goes with the rest. I'd go black pebbles or something light in a similar hue to the stone foundation feature. Or maybe scoria?

The conifer (blue-green) isn't doing too well but the star jasmine looks as though it just wants a bit of liquid fertiliser for extra nitrogen. It should then flourish and fill the boxes and you could then keep it clipped in a formal shape. It's pretty forgiving and you could prune it back if you don't like it sprawling, and give it a feed after. You could try cliveas, dark strap leaved plants that look rather like agapanthus, except they have fantastic orange flowers about now, and tolerate dry shade. Their dark green leaves look good all year round.

It's always tough trying to find a hedge that will grow in sun and shade, especially when you want a uniform look. Having said that, it isn't uncommon for designers to use a couple of different species - for example one species to boundary fences with another to the front fence. I'd consider lifting the canopy of the existing trees to let light in for more even growth across the hedge, however I'd still expect it to be a bit uneven due to the varying conditions throughout the garden. Viburnum tinus is a good pick for both a sunny position and a shady position, it will eventually get to 2m height and can be kept as low as 1m. If this isn't large enough, you could also try Portuguese laurel, (Prunus lusitanica) which will get to 4m easily enough. Both of these aren't particularly fast growing, but with adequate water and food they should be good for your situation. Murraya is another one that will tolerate sun and shade, though not frost. You won't get as many flowers in shady positions, and it may look a bit straggly. Your local nursery may be able to advise on what is readily available. When you plant, preparation and ongoing care is going to be important as it look as though you have a few plants that the hedge will have to compete with as it establishes (your neighbours conifers and your pears). Digging a good wide planting hole, plenty of organic matter mixed with the back-fill, as well as regular watering and feeding until the plants get established. Much as the Flower Carpet Roses are tough (especially the original pink), I wouldn't recommend planting roses in anything less than 4 hours of direct sun a day. You'll end up having issues with blackspot and mildew, and they're not going to give you the neat box look that you want. Flower Carpet Roses (Tesselaar Roses) are a good tough rose, however some colours (cultivars) are tougher than others. Pink is one of the best performing varieties, and as suggested, reaches a bit more than the height on the label. That may not be true of all the different colours though. Be careful propagating any of the flower carpet roses, only ever for yourself as they are rigourously protected either with trademark names and/or Plant Breeders Rights, making it illegal to sell the propagated material under the flower carpet name, or at all (in the case of PBR). Good luck!