re: wait (seconds) - wait (seconds) seconds before parsing the rest of the script..
^
I was going to say its takes a timer & 1 line of code & a goto point: to enable this, but that does have the drawback that $identifiers & local vars are lost/altered, so a built in one would be nice, if just for those features (the local vars i think might be the problem children)
re: waitwhile (if statement) - dnt parse the rest of the code while the (if statement) is true
^
i dont like this it would be task intensive unless you could specificy how often it should reevaluate, and if your dioing that you might as well just use an IF statment in the code and a WAIT suggested above