Your setup isn't even untaring the files it downloads:

Using Tar:/usr/bin/tar xf "App-cpanminus-1.7043.tar":
The system cannot find the path specified
[download]

You're running windows, this isn't a path that exists, tell cpan where tar is, or look at how Strawberry has cpan configured. This 'custom' build of Strawberry called slic3r perl, is only going to muddy the waters IMHO.

As a side note, you may want to consider using a Linux system for 3D printing, or at least something like octopi. Besides being much easier to setup on linux, a friend was printing some parts for me only for Windows 10 to do an unexpected reboot to install security patches, 2 hours 30 mins into a 2 hour 45 minute print.