Read a couple of posts that helped to answer my questions.
1. https://blogs.msdn.microsoft.com/sqlcat/2010/06/09/identifying-query-compileruntime-parameter-values-using-xml-showplan-output/ by Peter Scharlock answered question 1.
<ParameterList>
<ColumnReference Column="@P5" ParameterCompiledValue="’1753-01-01 00:00:00.000’" ParameterRuntimeValue="’2010-04-01 11:01:05.000’" />
As you might imagine, the...