Hi Sai,
I think you need to think from system perspective..............
I mean we are controlling system, so you can configure the system to change the active employee to inactive (which includes delimit of info type) after contract end by an action using PA40.
Once i asked my senior the same Question and he told me like if you dont know how to do it, how can you expect system to automatically do it for you 
So you can make the system to perform the way you want, so i think you can either perform a Separation action with future date ( But incase contract extension happens it will be an issue)
The other option is to execute the action (separation or contract end) once contract ends.
The dates should be same IT0000,IT0007 and IT0008 if you are paying the employee from the hire date.
Usually hire date defaults as start dates for most of the infotypes as per standard setting in V_T582A.
IT0007 and IT0008 have a link , the Capacity Utilization Level is being fetched from Employment Percentage of IT0007.
As long as that doesnt change in IT0007, you can create a new record for IT0008 with new dates...
Hoepfully this helps!!!!!!!!
Thanks & Regards
JIm