(I must say you post is not quite clear on what your saying, and I'm not sure where you stand, Ryand)
So your saying that when the rich get tax cuts they get richer, that's common sense. Now my guess is that they get richer because they take the extra cash and reinvest it into their buisnesses and when you invest more money into a sucsessful buisness more jobs and more wealth are created. So we want the rich to get richer.
Keynsian economics does required government regulations, but government regulations are not keynsian economics. Keynsian economics believes that the government should grow larger, more civil servants and what not, when the private sector shrinks. Now the problem with this idea is that the government can NOT creat wealth, and in no way could it pay for it's self. Since it is a fact the government can not create wealth, when the government grows it requires one of three things needed to pay for the increase in size. One, sell bonds and take out loans;two, print more money; three, raise taxes. Now any one who has a credit card or a loan on their home can tell you, in the long run it will end up costing you more than just paying for something with cash on hand. Printing money causes inflation, and it ties into the loan part considering that if your lender relizes your money is no good when you go to pay off you loan, he's not going to loan to you anymore. Now, when it comes to raising taxes, it's the lesser of the three evils just listed, but when your doing all three it's the final nail in the coffin, specialy since the rich know how to put their wealth in places where the government can't reach, which forces the taxes to go farther down the wealth spectrum to the middle class.
Now to another point, the increase in government power in anyway is not desirable. Absolute power corrupts absolutly. This slipperly slope of government is best evident in the continues increas in salary for Congress. Not once that I'm aware of has Congress ever decreased their salaries. Also history points to this as well, I hope you are all aware of the government cycle, if not here is a brief overview. Every government tends toward tyranny, untill they reach a point where they are authoritarian and oppressive enough that a revolution over throws said government and then the country desends into anarchy or if every thing goes right, a new democratic(or republic) government takes place of the former, and then the cycle repeats it's self. The only way to slow it down is to fight goverment increase, for the people to flex their political might and say no to the increase in government power and size.