Like hippo, I don't really understand the questions(s) you're asking in the OP, and I agree with his or her recommendations here. That said, I can hazard an answer based on part of your post:

The exclusion of an entire word, not just characters ...

I think what you may be asking for is an alternative to  [^somechars] (an inverted character class) in an  [^somechars]* expression that will generalize to any pattern. Something like this may fill the bill:

c:\@Work\Perl\monks>perl -wMstrict -le
"my $pattern = qr{ \b f[eio]e \b }xms;
 ;;
 my $str = 'foo bar feeble macfee unfeeling fee fumble';
 ;;
 print qq{match: '$1'} if $str =~ m{ (bar (?: (?! $pattern) .)* f \w+)
+ }xms;
"
match: 'bar feeble macfee unfeeling fee'
[download]

The  (?: (?! $pattern) .)* sub-pattern matches "zero or more of any character so long as the character is not at the start of something matching $pattern." Contrast with the behavior of
    m{ (bar .* f \w+) }xms
(Update: Also contrast with  m{ (bar (?: (?! $pattern) .)*? f \w+) }xms (note  ? "lazy" quantifier modifier).)

Update: As a parenthetic note, the example above can be extended to show regex composition:

c:\@Work\Perl\monks>perl -wMstrict -le
"my $giant_sez = qr{ \b f[eio]e \b     }xms;
 my $not_giant = qr{ (?! $giant_sez) . }xms;
 ;;
 my $str = 'foo bar feeble macfee unfeeling fee fumble';
 ;;
 print qq{match: '$1'} if $str =~ m{ (bar $not_giant* f \w+) }xms;
"
match: 'bar feeble macfee unfeeling fee'
[download]

Again, contrast with  m{ (bar $not_giant*? f \w+) }xms