Its totally depend on your business....You can get the suggestion from Google Adwords Suggestion Tool...
It totally depends to your business and your niche.But basically i would prefer 4 - 5 kws for particular page.
I think that it's best to have 1-2 keywords per page. So if you're targetting a whole lot of keywords, you should have a lot of pages in.
well its 100% depends on your website but i would say the lowest keywords the better because then you'll have to invest less money and seo effort to promote.
It always depends on your content but i highly suggest that you target only few because you just have to focus on keyword that describe the most about your website.
mostly 3-5 are enough.. select those keywords who really describes your site.. though keywords really have no limit..as many as you want as long as it is relevant
if you are looking for the whole site then you can target 3-4 Kw maximum.. since SEO gives you results after a long time and more its an organic results.. as not similar as PPC.. Its better to concentrate on 3-4 Keywords in the starting and then you can change your strategy as according to the business.
It is better to target 2,3 keywords per page. If concentrating on more keywords for each page, it will be putting Google to confuse how to distribute page rank for each web page.