No. Many people with large dogs have hardwood flooring. Your dogs will scratch the floors and it will cause more wear; however, unlike vinyl and laminate floors, hardwood can be refinished in the future. Keep in mind that even under normal circumstances, your hardwood floors will scratch. That being said, as hardwood floors age they tend to mellow.

Yes, engineered hardwood can be installed directly over concrete if it is above grade. There is even a system available to install solid hardwood directly over concrete floors.

Compared to other products, you may find that tile and grout require less maintenance than other floors, but it is not maintenance free. Grout should be sealed and caulking needs to be maintained to prevent deterioration of the backer board.