AAE for ECC Proxy.....

Dear All,

We are working on SAP 7.3(dual stack) and have created a scenario on AAE for ECC-PI-FILE(Async) by doing the follwoing steps in ECC:

Created RFC in SM59
Creating Sender Id in SXMSIF
COnfigured the same in IS_URL

My Questions:

1) I feel this Config is interface specific So when i develop new Interface(Same Scenario), do i need to Create Sender/Receiver Id for each interface and assign the same for IS_URL for each interface ?

2) What additional config needs to be done when we have File-PI-ECC scenario (ICO) ?

3) Will the same Async config work for Sync scenario ?

Thanks.