I think the Nexus 5 is a great phone at that price point, it has a lot of high end hardware and a pure android experience. It also gets updates a lot faster than the other smartphones. The phone competes with other phones that cost way more.
Maybe you could try windows o.s. you can really good deals on the nokia lunmias. But android has really been improving in there updates and you can't go wrong with the Samsung galaxy s4 or the HTC one. If you are going to get a iphone i would wait till the 5s comes out, a lot of people think...
That depends on how much you hate it. It seems like you hate it a lot, but do you hate it enough to pay the termination fee. But i don't think I could stand a year.