create a logo with css3

Question 1

Well, since anybody is answering, here you have a draft to begin with

CSS

#logoMain {
    width: 100px;
    height: 100px;
    background-color: #f5f5f5;
    border: 1px solid #ddd;
    border-radius: 50%;
    box-shadow: 0px 0px 50px 0px #999 inset ;
    position: relative;
}

#logoMainafter {
  width: 100px;
  height: 100px;
  margin-top: -35px;
  margin-left: 55px;
  display: block;
  border-radius: 50%;
  background: -webkit-radial-gradient(50% 50%, circle cover, rgba(255, 255, 255, 1), rgba(255, 255, 255, 1) 12%, rgba(255, 255, 255, 0) 24%);
  -webkit-transform: translateX(-80px) translateY(-90px) skewX(-20deg);
  -webkit-filter: blur(10px);
}

#logoInside {
    width: 50px;
    height: 50px;
    margin: 24px;
    background-color: #fe0000;
    border: 1px solid red;
    border-radius: 50%;
    box-shadow: 0px 0px 15px 3px #a80000 inset;
    z-index: 23;
    position: absolute;
}

#logoMain:after {
    content: "";
    width: 50px;
    height: 50px;
    position: absolute;
    top: 2px;
    left: 57px;
    /* background-color: green; */
    border-radius: 50%;
    box-shadow: -19px 17px 0px 14px #e80000;
    clip: rect(0px, 12px, 63px, -110px);
    z-index: 0;
}

fiddle

Question 2

For more complex shapes I'd look at using d3js or raphael and the svg element with css backing it. Take a look at this example. There is alot of other examples on the same site of complex shapes you can draw with CSS with a little help from JS.

Question 3

This is probably not the best use of your time, drawing this in CSS. Use a graphics editor that is made for it and export it to SVG or any other picture format. The pain you need to go to code this is not worth it.