About packages, yes, technically you are right ... But, I would recommend doing it manually as your apps need not wait for the rebind to happen and in worst case scenario, if the rebind fails, it will not be when the apps are online.
As cogur8000 says, it is best to create indexes beforehand. db2 does data loads and sorting for indexes simaltaneously in the LOAD phase. also, multiple indexes are built at the same time in the BUILD phase. the exception will be when your IO system cannot handle such parallel operations.