The TOS of Blogspot will prevent you from selling ad space on your free Blogger account. While I think they allows users to sell/promote products, I don't think they would allow you to sell ad space. You can only sell so much space if you can seeing as the blog is not on your own domain.
It's easy to sell, I've done it myself. What you need is a nicely designed theme. Blogspot is like paypal "technically" your account can be shut down at any moment but unless your breaking copyright laws, spamming ect., all things like that you won't be shut down. All you need to do is have a nice popular blog, and also make sure your blog has a custom domain.
Yup their is no problem regarding selling ad spaces on your blogger. Google doesn't mind that at all.
Yes you can sell ads space on your blogspot blog but your blog must be getting good amount of traffic and have high rank so that advertiser get encourage to display their ads in the given space.
Yes you can sell ad space buddy provided you have a decent traffic. BUYSELLADS is a good website to get you started.
To advertise your blog you need to create backlinks from other blogs, forums, social networks, articles and press releases back to your website. Backlinks are necessary as they not only bring traffic via the links on other sites but also help you to get traffic from search engines. The traffic a website gets from search engines is called organic traffic and the traffic from other websites is called referral. One more important thing is to keep updating your blog with unique content, this would keep bringing the search engine spiders to your website on a regular basis and this would help list your blog on the top of search engine results
Of course, but you should improve your blog first and have thousand of traffics to attract somebody put your space, like banner or text link.
Definitely you can. The only issue is many companies may only looking at the the websites with their own domain. You can fix it by getting a new domain name and set up your Blogspot blog using that domain as custom domain.
Since rules and regulations have been changing over the last few years it would be better to get the permission from blogger before displaying ads on blogspot. Although advertising companies like Bidvertiser, Chitika and Adhitz are compatible with blogger yet it would be a better idea to get prior permission before getting into the act. I remember my Adbrite ads were withdrawn from my blogspot blog by Adbrite itself!