We don't have a widget or an example that resembles the pinterest UI concept. The datasource data fetching abstraction features and the kendo templates are good candidates for building blocks of such UI, should you go this way.
Regarding your second question: both the listview and the scrollview widgets rely on the datasource server paging implementation to retrieve the next set of data. This is performed automatically. You need to make sure that the service endpoint understands the passed paging parameter values.
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