The clock hack has no dependency on the news fader? They can be installed with or without each other, not sure if i completely understand you there.
Anyhow, the reason that it isn't added to any other except for the forum summary is because most other pages have a one lined login table, so adding it in there would stretch it down. However, if you want to do this, i would suggest the following.
In public_forum_summary
remove both lines dealing with $hf->[0] =~
In public_common.pl
find:
if($vars_registration{SuspendRegister} eq "true") {add above.
$show_logout .= '
<span id="clock"></span>';
$show_logout_noreg .= '
<span id="clock"></span>';
