Gravel or landscaping rock - it generally boils down to one's idea of a good thing becoming someone else's nightmare. If they're fairly new, haven't settled in and buried themselves, I'd make an attempt at raking a section of them up since you'd like to do some gardening. The rocks are not likely to prevent weeds. Failing that, many things could be planted just by digging holes down past the rock - a sort of rock garden, a garden with rock mulch. For an experiment on the inexpensive side, the big box stores like Home depot, Lowes, Wal-mart generally have seasonal garden centers with all kinds of things you could use - Arctostaphylos uva-ursi (bearberry, kinnikinnick) is a nice ground creeper with pink-y flowers in early summer and red berries later. Juniperus horizontalis (Creeping juniper) is a good filler and can spill over edges. There are low growing sedums, phlox subulata, artemisia schmidtiana "Silver Mound", as well as other easy care/no care perennials... and there are always the annuals for instantly gratifying a need for space filling color. If truly temporary digs, I wouldn't make a big investment, but would at least give myself something pleasant to look at and be out in.

I live quite near you and have considerable shade. Viburnums are a good choice; there is a big variety to choose from too. Other understory trees/shrubs for our zone include dogwood, pieris, rhododendron, azaleas, euonymus (not burning bush, invasive here!),and hydrangeas. I have a caryopteris that does well in medium shade with late afternoon sun, and a weigela that is also happy in shade. Also grape holly and boxwood. There are others, like daphne, that I haven't tried but are supposed to be shade shrubs. You have to be careful about which of the colored hydrangeas; some are "cold hardy" meaning the roots don't die, but the rest of the shrub will die down to the ground and you never get blooms. The labels will not tell you that! Others like "Endless Summer" do fine since they bloom on both old and new growth; and there are some that are native here that don't bloom pink or blue, only white, yet are reliable. Of the colored varieties, to get blue flowers you have to put peat moss or ammonium sulfate in the planting hole to get them the acid they need; otherwise they bloom pink. Rhododendrons and azaleas will also require acid amended soil to do well, but they can do very well For almost all plants we need to lighten up our soil to improve drainage. Easily done by digging in some vegetative material, sand, pebbles etc. The county soil and water district is offering plants at great prices right now: Here is a link that might be useful: budget friendly plant sale from Franklin County

The fountain is a lovely focal point for your yard. I have a friend with a large pond and waterfall and it is wonderful but a huge amount of work. It's always something! They have numerous Koi and goldfish which produce new babies every year. Not long ago the pond attracted a heron or egret who decided it looked like a nice dinner spot. And the leaves need to be fished out and algae needs to be dealt with often. Another time the fish got sick from some parasite. And and and... Yes, a fountain offers all the ambient water sounds with much less trouble.

I'm not in So Cal, but I did just have our pool done with Midnight Blue Stone Scapes Mini's with Tahoe Blue Plaster. It's alittle darker then the Tahoe Blue which was the look we were going for and it came out perfect. We have not been in the pool yet other then on the tanning ledge some and it feels nice and smooth. Will get a picture up tomorrow when I am back at the house.