This may only answer the first part of your question:
ExifTool is a platform-independent Perl library plus a command-line application for reading, writing and editing meta information in a wide variety of files. ExifTool supports many different metadata formats...as well as the maker notes of many digital cameras...
You can find ExifTool here. It looks pretty handy, I'll be installing it today. It looks like it will output a csv with all the metadata you want. That csv is what a program would use to burn into your video.
As far as burning the data into your video, I'm not finding anything online that would take any sort of data set and burn it onto a video or even to a jpeg, especially without "Pro" software.
I would be interested to hear your solution to this, if any. It seems just putting the raw metadata in there wouldn't serve much purpose, because of the framerate. It'd be nice to see some sort of graphical ebb and flow of the data, again, don't know how it could be done without paid software.