How to consistently style the titles of Views in my Panels sidebar?
You just need to target it with css.

.pane-region-class .pane-title h2,
.pane-region-class .pane-title h3 {
  font-size: 16px;
  etc.
}


I think you can add classes to panel regions. And do the above without h2 / h3 to style the general title.