First point: If the fund will be used for infrastructure development, how will it grow? Can someone explain?
Next: If you allow politicians to play with the fund, they will surely use some amount from it on the name of "operation charges/maintenance charges/etc", and eat away a thick amount from it.
Last: Best way is to remove EPF. Keep PF complesory. But make it completely PPF. Allow nationalized banks to keep the PPF accounts. Employer's portion should be credited to employee's PPF account. And employee should be given the freedom to invest his PPF amount to stocks.