Hi there,
this is the incorrect content area for these queries (questions 1,2 and 4). You need to post this on the dataservices blogs or similar.
From the BW side, the openhub functionality is all part of the BW functionality, you do not need seperate licences to set up an openhub dataflow in BW
BW process chains are also part of the overall package, and are just a way to trigger several events serially, or one after the other, I would recommend trying to set up the process chain in your BW system.
I believe that when you set up the openhub in BW, the BW system will provide the correct API once you choose to transfer data via API.
I would advise to test, test & test more, from the BW side. I cannot help with connector advice,
thanks,
Colm