There is something odd about several of your MPG files. Media Info reports that the one linked above is 26:46. However, when the source file is moused-over in Windows it's shown to be 12 hours and 44 minutes long. That may be an irrelevant reporting error?? Nonetheless, it loads in VP and immediately plays audio in the normal manner. Why that's not the case for you is a mystery. Then there was the earlier SkyDiving video that is corrupt. Hopefully, you downloaded the repaired file linked earlier.
On the off-chance that there has been VP file corruption, please try this...
Close Videopad. Using Windows Explorer (the file manager) delete all files in these folders. Then, reinstall Videopad.
"C:\Users\<PC name>\AppData\Roaming\NCH Software\Components"
"C:\Program Files (x86)\NCH Software\Components" (or similar path without the X86)
The files that you deleted will be reinstalled automatically.
Asking any editor to load 35GB of content is not practical, IMO. One thought on how this might be handled is to load only a few files at a time, complete editing and then export. They become a composited clip - no individual edits. Later, when this has been done for all clips, bring them into VP and merge them together for the final export