Yes you can use a normal Windows drive share to connect from the Qlik Sense server to the folder/directory where you have the QVWs on the QlikView Server. Someone with administrative priveleges has to set up the Windows share. Then the QVWs can be accessed as files through a folder connection in your Qlik Sense load script or Data Manager.
No - installing QlikView on the Qlik Sense server will not help you with connecting the two at all.
Yes you can reuse the data model and the loaded data for any of the QVWs made by QlikView by using a BINARY statement (a so-called BINARY load) as the very first statement in a Qlik Sense load script. This will load the entire data model with it's data into Qlik Sense before continuing and executing the rest of the Qlik Sense load script.