So there are actually 2 questions from your posting.
The first question related to the capability to disable the pagination bar of the content list.
OOTB, there's no configuration option to disable the pagination bar of the content list. However, you can write a plugin to disable the pagination bar. There are a couple of existing postings related to that question.
https://w3.ibm.com/w3publisher/ecmforums/forums#/discussion/1233/whether-a-pagination-bar-added-in-308-can-be-disabled-by-custom-plugin
https://www.ibm.com/mysupport/s/forumsquestion?id=0D50z00006bi1fPCAQ&language=en_US
The other question related to the page size setting. You can also do this in a couple of ways.
https://www.ibm.com/support/pages/number-rows-retrieved-ibm-content-navigator-icn-search
Through a plugin: https://github.com/ibm-ecm/ibm-content-navigator-samples/tree/master/SearchPageSizePlugin
but beware of issues noted in https://supportcontent.ibm.com/support/pages/issues-viewing-documents-worklists-have-many-workpackages?check_logged_in=1
and there's an issue when specify the page size to be 0 using this plugin which addressed in defect
https://jsw.ibm.com/browse/DBACLD-12661.
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