You did a lot of good things there.
- In your log it says both "is corrupt" and "is missing." I'm not sure which one to believe. Could you browse to that location to see if it's there?
- Have you ever had KM working on that Mac before?
- Have you tried running in Safe Mode? (Scratch that idea. It probably won't help.)
- Have you tried running Disk First Aid? (Other people have had similar errors and it was a HDD corruption problem.)
It almost sounds like maybe your installation app is corrupt. Try re-downloading from https://files.stairways.com
If these ideas don't work, I probably can't help. I'm just an average Joe here.