A) Does it help to link to an xml sitemap within the site (not for Google/Yahoo/MSN) for secondary search faciities and crawlers? Even if there is a seperate html sitemap provided?
B) I’ve noticed some search engines requesting the xml sitemap address on submittal.
Do some give preference/wider coverage for sites providing this manually?
There is no reason to link to the XML sitemap internally. Some sites link to it from their robots.txt file, but the only benefit of that is letting the search engines know it exists. If they already know it exists then this does not provide any additional value.
That true I am completely agree with revium as it only proves beneficial when search know it and from this Google bot will able to crawl it and this help in indexing our site.