Sure, why not? But unless your facebook page is getting an enormous amount of hits every day, I don't see how you will be able to make any money by doing this.
I like a 2 piece crank because they tend to be stronger and less prone to failure.
I've ridden both Haro and Redline bikes and they are both excellent. I would say neither is better than the other - it all depends on which model you get. I have never ridden a Dans Comp bike so I can't really...