Hello Martin,I found a blog which may help you with your third question.First of all the blog which explains a solution to your problem very detailed: https://community.sap.com/t5/technology-blogs-by-sap/how-to-call-protected-app-from-external-app-as...

Hello Yessica, it has been quiet a while for me since I developed this software, but I will try my best to help you. Currently I have no chance to test this on a real SAP-System. You can try to access the API with any HTTP-Client, but i highly reco...