I'm on Catalina myself, so I can't test if these work with QuickTime Pro, but KM has a series of actions for controlling QuickTime that can be used without QuickTime being the frontmost app, including frame-customizable forward and backward skipping: QuickTime Actions
Just make sure any macros that use these actions are in the built-in Global Macro Group or other non app-specific macro group so that they can be used universally.
As for the timecode, KM can indeed extract and paste that as well, with a little AppleScript and math:
Insert QuickTime Timecode.kmmacros (2.8 KB)
You may need to modify the first line of the AppleScript to say tell application "QuickTime Pro" to get it to work with QuickTime Pro 7 (again, I'm not on Mojave, so I can't test it myself) but once that part's working, it should take the current time of the frontmost video in QuickTime, format it as 00:00:00, and paste it automatically.