Thanks Samuli, the first issue regarding the HTTPS has been solved after enabling all logon procedures for the ICF services in SICF.
Yes, I did add the IdP URL into the trusted/intranet security zone in IE and it still doesnt work. Attached is the screenshot of the exact error. 
I also added the entry to the HTTP_WHITELIST table in the backened abap as mentioned in the help.sap site in table in addition to the whitelist.ini.
Let me know if you can think of anything else.