Currently I've only the reset circuit described in the AN461 : a diod, a capacitor, a resistor Not literally, but as I read the errata it says "if you do not use a supervisor, you will lose your vector".

Then, when inserting the call to the GoToBoot, I've to manually reset the micro to download the code. So it's half-working but it allows me to recover my bootvector now.
This should tell you that the watchdog reset does not happen.

This is really a problem that Philips allowed to put this bootvector in flash
Agreed, the official explanation is that if you insert your own bootcode, you can change the vector to point to it, to which my reply is: "BS, if anyone have their own bootcode, it is not going to be activated by holding signals high and low during reset".

Is using the IAP will eliminate these troubles ? I've to evaluate it.
As you state, the NoTouch does work for you, you just need to teach the puppy to bite.

Erik