I've not heard that. How frequently is the site updated that probably has more to do with it than the host.
hi well yahoo has given option to upload our customise site through ftp, so if you can do good seo for your site then definitely it will come in top 10 rank in google. because search is looking for good contents, meta tags, and other seo features.
the yahoo.com domain is really highly ranked and heavily crawled. a yahoo answers post will be crawled as fast as in minutes. now if you host a site there, i dont see why crawling would be any different than any other host. it will take links to get the SE's to see they need to crawl it. though it is entirely possible that G would give MORE weight to the IP range that is Yahoo
No, because crawling rate generally depends upon the interlinking within the site, quality of the contents and or the dynamic nature of the contents etc and not on where the site is hosted.
Even if you have links, you would have to already be in the process of being crawled for Google to know about them It's simply a matter of adding more content, that will determine how often you get crawled.
The crawling rate mainly depends on the interlinking of the site, fresh of the contents , it's less affect where the website is hosted.