Those properties are not meant to be set declaratively from the layout.master file, they are set programmatically from code according to page settings.

It is not currently possible to style the breadcrumb links different according to their depth, you can enable them or not on any page at any level but you cannot make it only show certain levels or show some levels different from others other than creative css solutions that may exist.

ForceShowBreadCrumbs is not for making it show them on all pages and is not used in cms pages but in edit pages that are related to cms page features. Like in webstore for example, if you click the Store Manager link it goes to an edit page and this property is used to show the breadcrumbs while on the edit page regardless of whether the related cms page has bread crumbs enabled. Then if you click further on the Store Settings you will seeon that page it appends an additional bread crumb for the main store manager page, this is done with the AddedCrumbs property like in this code example from WebStore/AdminStoreSettings.aspx.cs:

Control c = Master.FindControl("Breadcrumbs");
            if ((c != null)&&(store != null))
            {
                BreadcrumbsControl crumbs = (BreadcrumbsControl)c;
                crumbs.ForceShowBreadcrumbs = true;
                crumbs.AddedCrumbs
                    = "<a href='" + SiteRoot
                    + "/WebStore/AdminDashboard.aspx?pageid="
+ pageId.ToInvariantString()
+ "&amp;mid=" + moduleId.ToInvariantString()
+ "' class='unselectedcrumb'>" + WebStoreResources.StoreManagerLink
+ "</a>";
} 

<portal:PageTitle is really a legacy control that was once used in the head  section of layout.master long long ago in the 1.1 framework version of mojoPortal. Joe Davis has used it for a way to show the page title outside of the <title> which only shows in the browser title bar, so I ahve kept it around.

Unfortunately that control only works in the context of a cms page where it gets the page title from the currentPage object, but pages like login and register, search, sitemap, etc are not cms pages so the only place the title exists is in the <title> tag in the head of the document. The only solution that comes to mind is to make some little javascript widget that reads the document.title and displays it in page markup and use that in layout.master.

I don't have any suggestion for displaying parent page titles on child pages.