Copy / restore files from Time Machine Backup Volume without Permission Denied Error

To answer my own question. I found the very simple solution many weeks later, because i'm usually not using the original Finder:

Use the original FINDER to copy from a Time Machine Backup, instead of Path Finder or the cp command!

Doing so produces a copy without having the mentioned problems. BTW: After i did this the first time, now also using the cp command works without the problems.

Background:

Time Machine alters the ACL (Access Control List) of all the backuped files, to make sure, the backup will not be deleted. Copying using the original Finder cares about this special case and removes these ACL entries. In this answer, you can read more about this.

But it looks like copying the first time with original Finder, seems to change also something in the system or on the the backup volume. Because now, also copying with cp command works without keeping the problematic ACLs entries. Even after reboot. While to copy with Path Finder stays problematic from the Time Machine volume.