Hi,
those are the old wrong roles which point to the old SRM5.0 transactions.
Please assign the /SAPSRM/EMPLOYEE_EHP1 or higher (of course better is to copy them and adjust to your needs as the authorisations are not completely filled in as a security measure to force you to use your own 
).
SUS is not part of this problem. The HTTP connection to ECC is for the harmonized roles so you can view ECC purchase orders in SRM as well.
The NWBC works on basis of the roles you have assigned in SU01.
Regards,
Robin