First I want to thank you all for all the help, especially to my friends Carlos Lopez Figueroa from Mexico for putting me on the right track, and Shawn Hopkins.
Second, the right way (in my case) to do update/delete array parameters is using this simple code that was posted in this thread ArchiCAD-Talk: LIMITING RANGE OF PARAMETER ARRAYS (special thanks to Braza from Portugal, see attachment).
Here is the script (adapted to Graphisoft Style recommendations):
dim setval for i = 1 to n if i > vardim1(val) then setval[i] = 0 else setval[i]=val[i] endif next i val = setval parameters val = val
Third the most important part, Why the hell my past code did not update my arrays !!!
Well it happens that this line script in the Parameter Script tab did give me all the trouble:
n = APPLICATION_QUERY ("PARAMETER_SCRIPT", "FIRSTOCCASION_IN_PROGRESS", _isFirstRun)
It appears to be that this past line was preventing the arrays from being updated, and to by pass any issue that may result from consecutive value deletion you have to put a time stamp, as have been explained in other threads in this forum.
I will put this finding as an issue for Graphisoft Team.
Thank you all