I'm taking license and guessing what paving does to the left off the picture. What I'm trying to illustrate in the sketch is placing the two cherry laurels, balanced (and centered as a group) in the bed space created by the paving. A plan view that accurately shows the pipe location would be useful. If the irrigation pipe is still exposed as shown in the picture, I'd move it as necessary... rather than plant the most major component of the landscape unbalanced and off center. If the pipe can't be moved then I'd try to fudge things as close to correct as I could get them. Can't see how the pipe lies in plan view, but c. laurels might work out in front of it. (Would need to see plan view to know.) Keep in mind that these plants are trees & will get big, unless you keep them rigorously sheared. If you don't, you'll need to limb them up to keep them from eating up the patio space. If they're limbed up as they grow so canopy is overhead, they could be closer to the walk without being in the way. Unless you plan to let the Lady Banks heap over the top edge of the fence, I can't really see how it's going to fit in that spot. It's a big, huge heaping thing. Think half the size of a car.

Need more details before realiable answers could be formed, What cultivar of Cherry tree are you planting? Which root stock is the featured cherry tree grafted onto? What is your USDA temperate zone? I am wondering if your location must be quite mild or even more often cold than moderate if your Sunset zone is only a 2 or 3. Is this an ornamental cherry tree, or a fruiting variety. If not ornamental, you might get more reliable answers if you post your question on the fruit trees forum.

To close for my thinking. I see far too many nice trees out grow their area just when they are starting to mature a little. Give them some room, they won't disappoint! Ron

Palm trees have tap roots, like carrots. You should be able to plant your plumeria trees within 5 or 6 ft ft of the palm tree. We dug up 20ft plus Royal palm trees, after they froze. Their roots were about 1 ft around the actual tree, but they were 5 ft deep. see picture of one we dug up.