Shall I replace my Nikkor 18-105mm lens with Nikkor 35mm F1.8 or sell all the nikon and buy X100?

Hi everyone here in DPREVIEW,

I have Nikon D3100 and lens 18-105mm. Most of the time I find it to large to travel and another problem is that the image quality is not good at all. I'm never satified with the image quality of my D3100 with this lens. But i read many reviews that prime lens will give sharper image than zoom lens.

Now, i have 2 questions:

1: If i buy 35mm lens, i have to sell my 18-105mm because i don't want to have both. Just want a lens that go with me anywhere. I don't mind about the lacking of the zoom. Will this be a good choice?

2: How is the quality of 35mm F1.8 with Nikon D3100? If it's still not good, i'm considering of selling both of them (lens + body) and buy X100.

Thanks you