Communication between Uipath Studio & Uipath Orchestrator

Hi ,
At present i am part of Architecture design team, while in the process I have come across few doubts about the Uipath Process, can some one please help me out with the below mentioned doubts,
(1) Do you need the uipath studio server for the orchestration functions?
(2)Can’t you connect webbased to the orchestrator and control the execution of robots, without utilizing the uipath studio server?
(3)How the intra application communication works , if it is HTTPS? Does it use its own certification or can it use custom certificates?
(4)How about robot communication to application? Can the robots use custom certificates? Or support https?