pineteam
Hi
1: I'm flying in "alt" mode with the A/THR in CLB thrust or TOGA with AP ON or with AP OFF but following the FD the aircraft will accelerate over VMAX without any reversion mode or protection?
As RB pointed out if you were in THRCLB at ALT* it will change to SPEED and protection is available. But if you were in TOGA then unless you bring THR levers to CLB speed mode cannot engage and over speed will occur.
2: same conditions but now we pitch fully down with CLB/TOGA thrust in alt mode, still no protection?
The protection I mentioned is FMGS speed protection only available in OPCLB/OPDES with AP off. In this case ATHR is in THRCLB thrust aircraft will continue to accelerate till FLT CTL high speed protection activates.