It's great that you were able to identify the species of the plant and found some to plant along your walkway! It's disappointing when they don't thrive as expected, but it sounds like you're planning to give it another shot in 2023. Maybe checking out a California super bloom wildflowers guide...
It's been a year but, sounds like you're gearing up for some serious valve work and porting. Both stones and carbide cutters have their pros and cons. Stones are great for initial shaping and can be more forgiving, but they wear out faster and might not give you the precision you need for fine...
For the cables, you can use a silicone-based spray lubricant, which will provide a protective coating and reduce friction on the cables. Be sure to avoid using any oil-based lubricants, as they can attract dirt and debris and cause the cables to wear more quickly.