Yes, The dynamic pick list is actually a B.C. that is popped up when run-time is set to true ,and as we know we can add as many fields under one B.C.

As in a static drilldown configuration, the drilldown object definition identifies a hyperlink field and a view. These property settings continue to have the same purpose in dynamic drilldown, namely, to specify the list column or control that has hyperlink capabilities and the destination view when the hyperlink is clicked.
However, in dynamic drilldown, the drilldown object also has dynamic drilldown destination object definitions, each of which points to the type field in the business component and specifies a value to look for there. When the value in a dynamic drilldown …

 
Virtual business components (VBCs) are mechanisms in Siebel EAI by which data from an external system can be viewed in Siebel applications without having to replicate that data within the Siebel Database.
 VBCs are configured in Siebel Tools and use Business Services to access data from an external system. VBCs can use standard transports like MQSeries, HTTP, and MSMQ, along with the XML Gateway Service, to query, insert, and update data.

Puru , Reader or our website has shared excellent description of above question.
1.  Based on Usage: DP is used to draw/pick a value for a field in Originating BC from any BC  whereas MVGs is an alternative to a detail view for managing parent and related child records. It allows complex queries that span multiple BCs