By default apps running on hcp use saml for authentication. If you do not have trust setup between hcp and the server you are running from you will need to declare a neo-app.json with the following
{
"authenticationMethod": "none",
}
which should make your first scenario work, but if you intend to load the app in FLP you should use jQuery.sap.includeScript.
Point b will try to load the library from your app which is not what you want. For the last point the thread you linked should provide the relevant info, but this will only work when the app exist on the same server or your create a proxy for the library.
Regards,
Jamie
SAP - Technology RIG
