I made some progress, and now have the axes correctly labeled. However, I'm still encountering the problem of not being able to correctly specify the axes limits. Below is my full script & a description of the specific problem:
% If I use this, the left Y axis becomes extremely compacted... % ylim([-2 2]);
If I adjust the left Y axis using the Ylim() function, instead of having these [-2, 2] values span the entire left Y axis, these values are instead compacted (and interestingly, these left-Y-axis values do not at all match up with the right Y axis scale's values). Again, as I mentioned in my previous post above, using Edit --> Axes properties only affects the left Y axis, and accomplishes the same incorrect change as calling ylim().
To summarize, I'd like my left Y axis to have limits of [-2,2] (without being squished into a small area of this axis) and the right Y axis to have limits of [-20,20]. And I want my 2nd data set to have substantial markers so that the plotted values are visible, instead of being single pixels. Thanks for your suggestions.