After taking a quick look at the code I can confirm this page has no pagination. The 100 limit is not correct though. It has a limit of 50 per answer, comment and question. That means you can have a total number between 0 and 150. There is no way to configure this. You'll have to create a feature request for 1.8 (as I guess 1.7 backlog is already full).
Regarding older posts not showing up it is just a matter of refreshing the page so that the query is run again. If you consider this is something critical then:
1. Open file qa-include/qa-page-admin-moderate.php
2. Locate this:
list($queuedquestions, $queuedanswers, $queuedcomments)=qa_db_select_with_pending(
qa_db_qs_selectspec($userid, 'created', 0, null, null, 'Q_QUEUED', true),
qa_db_recent_a_qs_selectspec($userid, 0, null, null, 'A_QUEUED', true),
qa_db_recent_c_qs_selectspec($userid, 0, null, null, 'C_QUEUED', true)
);
And add this line immediately before the previos text:
@define('CORE_HACK_MODERATE', 1000);
3. Open file qa-include/qa-db-selects.php
4. Locate function qa_db_qs_selectspec
5. Change this line:
$count=isset($count) ? min($count, QA_DB_RETRIEVE_QS_AS) : QA_DB_RETRIEVE_QS_AS;
Into this:
if (defined('CORE_HACK_MODERATE'))
$count = CORE_HACK_MODERATE;
else
$count=isset($count) ? min($count, QA_DB_RETRIEVE_QS_AS) : QA_DB_RETRIEVE_QS_AS;
6. Repeat step 5 for functions qa_db_recent_a_qs_selectspec and qa_db_recent_c_qs_selectspec that are located in the same file
This will filter up to 1000 for each type. Not the same as pagination but it is a quick and dirty workaround :)
A cleaner way to do this is to find the @define('QA_DB_RETRIEVE_QS_AS', 50); in qa-include/qa-db-maxima.php and change the 50 into a 1000. The thing is it will affect other lists (not sure which ones) while the steps I've given you will only affect that one.