"You can get more with a kind word and a gun than you can with a kind word alone" -Al Capone-
Those days may have come and gone. In today's corporate world you do not have the ability to be rude, pompus or arrogant. There are 5 other people waiting to take your job, and if you are not liked by other associates and ultimatly your managers it makes it that much easier to can you. Have you ever had a manager who you WANT to work for? I bet they weren't an ass, so why should you be? If you want to lead people one day learn from the people you admire and soak up their skills and ability to work and lead other people. I will consistantly try to get as much face time with co-workers who inspire me so I can find out as much as possilbe about what makes them tick.
However you need to remember that being nice is only one part of the equation to be successful, you also need to produce, and best yet is to be good at both.
In term of seperating my personal and professional like I've worked by this rule:
-Leave emotion and personal issues in the glovebox.-
I have found this to be very hard for so many of my college counterparts, with streaming access to networking site or just a constant stream of information via txt, black berry, iPohones, iPods, etc it is so easy to get caught up in some personal emotion. If you are having a personal problem such as your significant other leaving you, leave it at home where it should be. Bringing these types of conversations up in the work place could spell doom. It can easily send all the wrong signals. So if you don't want to hear other people complain about personal issues make sure you don't do the same!
I would recommend watching this video. This may be one of the most moving and influential videos I've seen in a long time and it will change your outlook on life and the issues you have. It's 1hr 20mins long so make sure you can watch it all.