You shouldn't need to run RM in compatibility mode under W10 - we do test under W10 so if you have found some issues that you think are W10 specific then I would be interested to hear about them.
I would strongly recommend that you calibrate images within Google Earth before importing into RM. If you do this, and import via the KML/KMZ file, then RM will split the image into tiles (in an MBTiles database file) which gives much better performance when viewing maps within RM. If you are only looking for GE background image snapshots, then an easy way to generate these is to zoom to your required area within GE, save the image background (in the highest resolution possible) and then immediately add an Image Overlay to GE without moving from your current location. You can then choose your recently exported image file within the overlay properties window and stretch it to fill your current view. This should align the image pretty well (you can vary the overlay opacity to check this). Once done, export the overlay as a KMZ file and import that into RM.
As others have alluded to, there are other ways of acquiring background imagery for RM. What you are looking for is a way to generate MBTiles files, which RM can use directly. Have a search for SAS Planet.