ESX5 support was added in BSA 8.2, don't know if it has been back-ported to a 8.0 SP.
Yes, I believe 8.2SP1 added VC 5.0 support and 8.2SP2 VC 5.1 support.
Did you deploy the DCO (Distributed Component Object for Virtual Center) against the VC?
Also your error states that its having issues connecting due to "Invalid web service login credentials. : on host MPPDADC165"
I would check
1. Web Services is running on your VCenter by going to https://hostnameofvc:443/sdk and make sure it returns a blank page
2. Confirm your credentials by logging into VCenter with the same one you used in configuring the connection.
When I installed BBSA 8.2.04 and installe RSCD agent 8.2 on vCenter the issue is resolved. vCenter 5 is not compatible with BBSA 8.0