Regarding poker software it is useful for giving you reads on opponents in game especially if you are multi tabling and not able to concentrate on every action on each table. Also it is good for reviewing your own play and plugging leaks, noticing patterns etc.
From your op i presume you are a recreational player and you play poker for the enjoyment of it, if poker office is stopping you enjoying it then stop using it. I would argue that not using poker tools will in the long term hold you back from making more at poker, but that is up to you.
I don't see how it should change your style, it is simply giving you more information on your opponents. Though in sngs there is pretty much bar the early game, only one optimal style.
Lol at this being a must from very bad weak players, if you compared players using this software compared to ones who aren't, i know which group will be doing better at poker. It will not be anything to do with the software, it is just people aware of the software are more likely to want to improve their game and maximise their hourly.
There is a lot more out there then poker office as well -
http://blondepoker.com/forum/index.php?topic=32646.0Welcome to blonde.