I have a friend who has been for the interview last month and confirms there is no bond money deductions for DEC's.Infact he has been offered right seat B777 and after 500 odd hrs (subject to performance ofcourse)upgrade to command and has been told nomoney deducted towards bond.If you leave before 3 yrs,you cough up the money and clear all dues etc.
about waiting period,it seems they are inviting people as per ones experience and background.
good luck to all.