Straddling rubber to take signs

[buckweat]

During a discussion about straddling the rubber and taking signs and obviously trying to deceive the runner, here is the statement from one fellow.

"it is legal to deceive the runner. That's the whole idea after all. You want to get the runner leaning the wrong way so you can pick him off. It's the runner's responsibility to read the move and not get picked off.
There are, however, limits as to what moves you can make in doing so. The one described is not on the list of illegal moves that cause a balk [which are in 8.05 plus the failure to come to a stop in 'set' in 8.01(b)], therefore it is not a balk."

My counter was:
" If you really get technical, since taking the signs off the rubber is in 8.01 Legal pitching delivery, to me if its done, it makes the pitch that follows an illegal pitch since it wasn't delivered illegally.
4.03 says he has to take his legal position while in the act of delivering, so if he doesn't that makes it an illegal pitch which is a balk.
8.05 says the balk rule is to prevent the pitcher form deliberately deceiving the runner and since 9.01(c) allows the umpire to make those kinds of interpretations and judgements, it seems that its up to him."

My argument isn't whether or not it is a balk as written in the rule, but that the umpire has the discretion to make a judgement and if he wants to, could call a balk.