I've added a link to one of the photos below. Instead of changing materials, I'd either add more of the same concrete, or have the existing concrete resurfaced if possible to blend with a new pour. Or maybe the new areas could be concrete in smaller sized blocks or stamped with a pattern, but the same color. I'd leave some planting pockets along the fence where the stone is now, so you can put in something to soften and break up the fence. I'd use a privacy fence on the back and side, so you don't have your neighbors ogling you while to relax poolside. Not a "stockade" but a solid board, or one with smallish spaces between the boards. Here is a link that might be useful:

You could have someone come out and point out to you, as some of us have already done, what your choices are and the advantages and disadvantages of each, but what is the point of repeating what has been done here? If you are unclear about the choices, you can still ask questions, trying to get the issue clarified. In the end, you must evaluate what solution will work best for your lifestyle. Once you decide, it would be good to hire a designer to work out and fit together the pieces of the puzzle. You wouldn't want to solicit multiple design ideas from unpaid designers. The best you would get are vague, general ideas ... because designing is the process of working out and refining ideas and no one is going to invest in your project unless you are paying them. You just need one good, workable plan and one good designer. You could interview a few designers to find one whose personality and work you like. If the designer is good, you might not even care if they have a bad personality :-) Or ... if you or hubby have the ability to do the design, you can work through all the issues and commit the project to paper. I'm sure people here would give feedback on your efforts as you go along, trying to help you stay on course. But doing it yourselves means that you will be making the final call on all decisions. Or maybe you'd just want to do preliminary design work of getting the basic layout thought through and then turn it over to a pro to fine tune and make it buildable. You ask "if we redo the wall, why not a patio?" What's going to be the most useful to you ... a large expanse of floor connected to house floor level? ...Or having that expanse split in two levels? Given the overall lack of depth for building either, I'd think the single level deck would be the most enjoyable. If you need more room later, it's likely that your best option for expanding is to go from deck level up one step to an upper patio.

Thank you Dig Doug, this is a great design. The only thing we need to think about is how the stairs will come out into the patio below, given the location and slope with the rise of the new deck. All of that may be feasible though. We are definitely going to consider this design. thank you so much.

Maples have lots of surface roots and water on a hill is in short supply. Once the maple is mature, it will be the only thing living on the hill. And it will eventually find the drain. A ridiculous statement. Look at any wooded area--maples live on slopes much steeper than that and with other trees as well. Look at large parks/arboretums where maples share ground on slopes with other trees and shrubs. And maple roots don't search far beyond the drip line of the tree for water. Good grief! Maples are not the terrors of the woods.