the major difference between an angel and a VC is that the former normally invests his own funds. on the other hand, VCs manage a pool of money invested by others through a fund.
secondly, VCs mandates are not to rape your business. their goal is to make money. whether they end up raping your business by trying to make money is another topic all together. that is why it is important to find the appropriate VC for your business. if you find the right one and play it right, you should not get 'raped'.