This does not print out any results for key or errors (lines 211 and 212)

Riales used this to get the $key:

$key =~ /^LOGGED IN (\w+) GET/;
$key = $1;
[download]

Whereas you are using this:

$key =~ s/LOGGED IN //;
$key =~ s/ GET //;
$key =~ s/ POST //;
$key = $1;
[download]

In your version you need to leave out the last line: $key = $1

How do I grab all of the col1_vals together in order to run an average

Riales code
my $calcd = calculate_stuff($seen{$key}->{col1_vals});
covers this. All of the col1_vals are now in $seen{$key}->{col1_vals} which is an array reference - if you print that out you will see:

foreach my $key (keys %seen) {
    my $col1_vals = $seen{$key}->{col1_vals};
    print "@$col1_vals\n";
}
[download]