BPMN (PO 7.4) best practises

Hi Experts

I created a simple BPMN (PO 7.4) in order to study. I want to know if the created structure was a good one. The scenario is an outbound SOAP interface with two file inbound interfaces. For this, I created three iFlows.

1 - BC_System1 to BC_BPM

2 - BC_BPM to BC_System2

3 - BC_BPM to BC_System3

In addtion, the BPM process screenshot

First of all, I want to know what's the best way to create the SWC structure? I created a SWC BPM, is it right?

Where can I add the message & operation mapping objects?

Is it better to create the mappings objects under the BPM SWC?

Is it better to add the operation mapping in the iFlow or in the BPM process?

Thanks,
Leandro Silva