I can't get RM to (drag to calibrate) my JPEG image in global view, I can't get the drag handles to activate on the image, once or twice I got the drag handles to activate, but if I try to make a second adjustment the drag handles go inactive and I can't get it to do anything.

I'm not sure why this is happening, but perhaps a screen shot would help? Which RM version and which Windows version are you using? Are you using a mouse or a touch device to calibrate?
One option, which is perhaps preferable for other reasons as well (tiling images into MBTiles format on import), is to calibrate the image within Google Earth as a Ground overlay. You then save this file - a .kml file and the original image file - and import into RM by selecting the KML file.