idg: The vertical dev. bar should be right where it is supposed to be if you have corrcted the alts in the FMGC.
As long as you dont fly it in FINALL APP mode there should be no problem with this. (Database validity problems)
How much i trust the controllers to make corrections i will leave unsaid. But they always let You start the procedure at the Altitude you deem necessary. (Advance notice buys you friends)
Happy Easter