One page site is possible but having as much important pages for your site/company needs is essential..
It doesn't matter even if you site has only one page in Google's eyes. Additionally, Google likes small size websites.
page quantity is not considered as important signal in G and 1 page or 100 page website treating same by Google so you can go with current situation it will get crawl...
1 is fine. We have a site with 5 pages (one is just a contact form), all with one or two paragraphs of text. It somehow has a PR of 4 ...
are you kidding? The more pages=more contents the keywords density are very important to let any search engine knows what is the culture of the website
There is no hard and fast rule for the number of pages that you need to have for getting your pages indexed. However, the quality and amount of content on the page will have a considerable impact on the SERP of your page.
The minimum is 1 but it's not the optimum. It depends on what you're going for, really, but you should mix your portfolio up with different sized sites. Like have 10 websites with 5-10 pages, 4-5 sites with 25-40 pages and have 2-3 sites with 100+ pages. Then just keep adding to that; this allows you to weather through algorithm changes and such so you're never scrambling because all your sites are doing the shuffle
you need just one page for cached your site by Google. There are no any limit of pages for cached by Google.