It's not totally risk free, it depends on how you make the doorwaypages. IMHO it is best to make doorway pages so that they are ok for human eyes also, Content rich pages that humans can read, will not offend the spider.
That is a very powerful statement, as all pages should be in a sense doorway pages.
Ok, lets say with careful navigation planning and keyword optimization you achive some what of a doorway (I still think it is not easy to do). But then to really pull traffic into each of your pages you need in engines that rely on link popularity a number of links pointing to each of the "doorway" pages. Then the links and pages from which they come would ideally be themed. Wow you are talking about a lot of work there :)
<<That is a very powerful statement, as all pages should be in a sense doorway pages.>>
Well!!you could say that, but!!
In my world, a doorway page is a page optimized for one keyword and one SE only. You use the content pages of your site to create pages customized for a specific keyword on a specific SE. Each page should be readable and viewable by humans.
If you are carefull when you creat your content pages, they will work as "broad/average" Doorway pages on the most important keywords/SE
It's the old, 'what is a doorway page' debate all over again. We've never been able to pin down a definition. Instead of just thinking of doorways as kw targets, we've slowly been expanding the scope to include 'side pages' that do have quality content. The content is there as a point-of-entry. You could say this very thread was a 'doorway' page. It's optimized and targeted at the term "doorway pages".