Routing Rule - ISO20022 CREDIT TRANSFER (CORE)

Community,

I see several standard ISO20022 outbound routing rule is available out of the box, and they all come with MESSAGE_FUNCTION = SEND_SEPA_CREDIT_TRANSFER, different RECEIVER as well.\

I have below questions when we are trying to configure it in our own.

1. what is the role for MESSAGE_FUNCTION and RECEIVER in ISO20022 routing rule?
2. we are not going to send SEPA payment, but normal supplier payment, shall we change the MESSAGE_FUNCTION? and where to change it? 
3. Shall we need to change the RECEIVER? IFS standard comes with AT_001.001.02_ISO20022, CH_001.001.03_ISO20022, CORE_001.001.03_ISO20022, FI_001.001.03_ISO20022, if we don’t change it, which one we should use then?

Thank you.