Hi!
1. Don't know about clustered physical servers support.
2. Did you check what "Web Service URL" are in "Reporting Services Configuration Manager" for your SQL Server?
In my case I have ITMS installed, which works through SSL via non default port 777
By default I see that in "Reporting Services Configuration Manager" is only single Web Service URL only for 80 port. I've added another Web Service URL for HTTPS - 777 port and see that connection was successfully verified for it.
Thanks,
IP.