I want to know about checking on a registered trademark for the purpose of changing the ownership name

Hire an IP attorney or see if anyone at the Trademark Office will talk with you. You need an attorney.

Graphic Designer hired hourly to create products for a start up business in Las Vegas, Nevada

If "hired" means the Asker was an employee then all belongs to the employer. If the Asker was an independent contractor then the evidentiary...

This is not an Intellectual Property issue. See criminal counsel.

Designing

The design for a utilitarian product is probably not protected by Copyright and there is no mention of a design patent. See IP counsel for guidance.

I'm a literary agent. A prospect client wants me to deal with his attorney instead of direct contact. Is this an unusual request

It is not unusual. The attorney is the client's agent for the purpose of contracting.

Consumer confusion is the factor of importance. Will a consumer be confused over which business is the source of the material they purchased the...

Which lawyers are best for copywrighting drawings.

Attorneys engaged in Intellectual Property issues will be best. See IP counsel.

Is it better to file trademark applications country by country in the EU, or to file a single EU application?

For Patents use the EU application. For EU trademark use the Madrid Protocol. See IP counsel and contact EU Counsel.

Do I need to contact the NCAA, NFL, NBA, MLB, NHL, MLS and respected teams to use their logo on a retail website?

Yes, you'll need permission to sell team specific apparel. See IP counsel.

Right to publicity vs. artistic expression in the sale of T-shirts featuring the single names of sports stars

The Asker seems to answer the question by the reference in the last paragraph. Use of a player's name may be a "right of publicity/privacy" issue...