I am Muslim, but I have to say, that your pastor is right in one point. Capitalism takes away from the poor and exploits them in the worst way possible.
On the other hand, you are right with ‘God Given’ free will and that it is immoral to support a large and corrupt government.
In my opinion, Islam has the solution as a middle way for both opinions. In Islam everybody is allowed to work and earn as much as he wants and to own as much as he wants. But because of the system of alms, which is % 2.5 of the money you stored for one year, nobody who earns money ever would store this money, but will invest the money, so the money is ever flowing. So although he is allowed to own as much as he wants a rich person will invest in the society, which allows him not to paying taxes, but at the same time the poor directly benefit from his investments.