I've tested the above fixes and they work (You can now double tap an image to select it). Works well.
I've noticed other mobile issues with the panel and will attach some pics below. Mainly, width/viewport doesn't correctly fit to the screen.
Device: Iphone 6
Browsers tested: Safari, Chrome
When you open the panel the width is too large for the screen (There's a horizontal scroll). This doesn't happen when you use chrome on a desktop to test responsiveness.
It seems some element pushes the width past 100% (You can see this on the second image where the KCFinder popup background fills the 100% width and the panel elements behind expand much further).
It's worth nothing this is the same logged in and out. The only change to this panel is the logo (Happens with the couch logo, also.)