Cisco Application :: ACE 4710 (1) SSL Certificate Import ( 2 ) With Load Balancing?

I am performing a deployment, in which i require clarity on the following. Our setup has DC and DR , in each site we have two devices for HA.We have received One SSL Certificate from Public CA, Kindly clarify the following doubts i have on thisIn Doc, i found Cert.pem and key.pem is required to generate the pair ,do i receive both Cert.pem and key.pem from the CA or we can generate key.pem from Cert.pem ?SSL Offloading is planned for the X application, and it is running in both DC and DR ( Considering each having their own Public IP address ) , do i need to have two different public certificates or a single certificate can i use in both DC and DR.Load Balancing IssueIs it possible to configure in ACE to access the service in Business hours and in non Business hours to display HTML page showing this is available only during these hours ?In DC we have Three Web Servers ( only in One physical server the service is active, other two are backup ), and these three servers are under cluster and shares one cluster IP , In ACE we have created the VIP and Pointed to only Cluster IP ( like pass through only ). The issue we face is if active web server is down, even then ACE is sending the traffic to that webserver only instead of sending it to the new Active web server. let us know if any solution is there to overcome this issue ?as per my understanding instead of giving cluster IP as real server IP we can issue the three physical servers. now i dont require load balancing between three servers instead require failover king like if first server is down then it should forward to Second server ?