About the Tahm Kench Q+W combo
There is currently a lack of incentive to do it. Other than extra style points, there is barely any reason to use that combo. It uses more mana, does the same damage as a standard W, etc. I've played quite a few Tahm games now, and have only used it once just to try it.
My suggestion would be to make the minion/monster you fire out deal extra damage if the Q was used to grab it, that's all there's to it.