A trademark is designed to prohibit competitors and others from using the mark of a company in a way that is likely to cause confusion in the marketplace. It does not prevent all use or copying of the mark. Share and Enjoy:

Yes. So long as there is no confusion created or any implication of a relationship that does not exist, a blogger can use a logo from a company to talk about them. Share and Enjoy:

Yes, so long as there is no confusion nor any attempt to to use the name and reputation of the trademark to further your own business. Share and Enjoy:

No. You can establish a trademark by using it with good faith in the marketplace. However, you are required to register your mark to use the “R” symbol. Share and Enjoy:

A trademark is a word, phrase, symbol or design, or a combination of words, phrases, symbols or designs, that identifies and distinguishes the source of the goods of one party from those of others. Share and Enjoy:

Google AdWords changed their U.S. trademark policy to allow advertisers to bid on, and include trademarked terms in advertisements. Google explains the changes here. While your ad may have limited serving in the U.S. under the new policy, ads approved under the new U.S. trademark policy that are not authorized by the trademark owner will not run on other Google domains. You should continue to request authorization from the trademark owner for terms[...]