How can I BATCH CONVERT Live iPhone images that have been imported to iPhoto as .m4v files to still .jpg images in MacBook OSX?
I see two possible options for you: Using the Photos app or Image Capture.

Photos app

The newer Photos app (that replaces iPhoto) was released as part of the OS X Yosemite 10.10.3 update. As you seem to be running Mac OS X Yosemite, presumably you have it installed on your system (by default in the Applications folder).

If you import your live photos into the Photos app and then select them (not sure I would select all 1000+ at once), you can go to File > Export and it will export the JPEG versions of the selected photos.

As an aside, if you Option-drag an image into the Finder or go to File > Export > Export Unmodified Original, then both the unmodified JPEG and the associated MOV files are exported.

Image Capture

Another possibility is to just use Image Capture (also by default in the Applications folder):


Launch Image Capture
Connect your iPhone via USB
Select your iPhone
Choose Live Photos images
Import the images


Both the JPEG and MOV files for each image should copy across to your MacBook.