My answer is based on CA law. Yes you can be in violation of Cal. Civ. Code § 3344, which is the "Right of Publicity" in certain circumstances....

Once you use your trademark in commerce, you are given "common law" trademark rights for your geographical region. If consumers are confused by a...

You should take these letters very seriously. Incorporating a trademark in a domain is considered trademark infringement. For example, you cannot...

Is there a strategy to developing my product line, advertise and sell without infringing on copyright and trademark law?

Generally characters from video games are protected by copyright and possibly trade-dress. I would recommend that you hire an intellectual property...