So far as the listing in google as to backlinks...google never shows what it sees really and almost never lists the important links..so that could be good in this case.
As for using sitemaps..I never use it for more than one. Each site has it's own account tied to it's main mail addy. As far as google is concerned I am non existent. And no other site is "kin" to it. What business is it of google's how many sites I have created or manage.