I have wrote a little test file in order to check prince.
In Order to be able to see the page begin and page end the top and bottom border for the pages are set to solid 1pt black.
The Margin from the elements at the begin of a page are taken into account and if an element is shifted to the next page (page-break rules) or overlap pages the element or it continuation is immediately printed out without margin. In order to get a correct representation I Have set margin-top:0; for all elements and assigned padding-top:12pt; to the page.
After an ul element I have a paragraph, the ul element don't have a bottom margin. The default margin values seem for me not to be OK.

Prince 9 does not add vertical margin to list elements. We have changed this in the latest alpha version, by adding this rule to the default style sheet:

ol, ul {
    margin-top: 1.12em;
    margin-bottom: 1.12em;
}