Here is a different idea for you... Instead of if/else, I used a "dispatch table" to take action on the various op codes. The default is to just do nothing by printing the existing line. If the op code has an action, then it is done (that might be "nothing" in the case of G92 or M190)

#!usr/bin/perl
use warnings;
use strict;
$|=1; #turn off stdout buffering, easier to debug warnings...

my %dispatch = (G92  => sub{return},
                G10  => sub{print "M104 S0 ; laser off\n";},
                G11  => sub{print "M400 ; wait for moves to finish\n";
                            print "M104 S100 ; laser on\n";},
                M190 => sub{return},
                G1   => \&G1,
                );

while (my $line = <DATA>)
{
  chomp $line;
  my ($op,$rest) = split ' ',$line,2;
  $rest //= '';  #define $rest as null string if undefined
  
  if (exists $dispatch{$op})
  {
      $dispatch{$op}->($rest);
  }
  else
  {
      print "$line\n";
  }
}

sub G1
{
   my $rest = shift;
   $rest =~ s/Z/Z-/;
   $rest =~ s/E[\d.]+//;
   print "G1 $rest\n";   
}

=prints:
T1
G1 Z-0.050 F7800.000
M104 S0 ; laser off
G1 Z-0.150 F7800.000
G1 X14.725 Y-8.975 F7800.000
G1 Z-0.050 F7800.000
M400 ; wait for moves to finish
M104 S100 ; laser on
G1 X14.725 Y8.975  F120.000 
M104 S0 ; laser off
G1 Z-0.150 F7800.000
G1 X-9.585 Y-0.615 F7800.000
G1 Z-0.050 F7800.000
M400 ; wait for moves to finish
M104 S100 ; laser on
=cut



__DATA__
G92 E0 ; want to remove all G92 lines (works now)
T1
G1 Z0.050 F7800.000
G10 ; retract
G92 E0
G1 Z0.150 F7800.000
G1 X14.725 Y-8.975 F7800.000
G1 Z0.050 F7800.000
G11 ; unretract
G92 E0
G1 X14.725 Y8.975 E0.01465 F120.000 
G10 ; retract
G92 E0
G1 Z0.150 F7800.000
G1 X-9.585 Y-0.615 F7800.000
G1 Z0.050 F7800.000
G11 ; unretract
G92 E0
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