Yes
yes
Yes.
Yes.
Yes.
Yes.
Yes.
Yes.
Yes, they are part of a major corporation and they would be protected.
Yes
Yes.
Almost certainly. And I guess they could argue that you were violating ther rights in common law with a name like "Dairey Queen."
A lot of trademarks and names are legally protected, but not all. For a trademark to be protected it has to be registered as a trademark, for which you will have to pay a fee. After that it is protected against other peoples use of it, but normally only in the country you register it for. A world wide trademark protection is costly and is very difficoult to uphold by law. As for names as in surnames, most are not "legally" protected as such, but when it comes to rare family names, one can not automatically take one without asking for the approval of the families first. Laws regarding this however vary from country to country.