Sting - Still is a big name outside of WWE and even though he's quite old, he'd still provide invaluable experience.
other signings would be; Amazing Red, Crimson, Eric Young, Jeff Hardy (depending on whether he gets clean), Pope, Jordan, Jay Lethal, RVD, Daniels, Kaz, Magnus,
Backstage Roles/manager/Non-wrestling capacity and keep around for experience:
Hogan - get off twitter, stop giving stupid interviews, and no creative input = if he agrees, he could be a big name to exploit.
Bischoff (stay off camera and he's underrated in a backstage capacity - he lets his ego get in his way on screen; Put himself in the NWO, hogging the immortal limelight currently etc)
I did agree in general with your list, but your list had too much of an indy feel to it. Wrestling is a balance between entertainment and action (but storytelling keeps a majority of people watching unfortunately) and you proved that with your lethal comments. You find him boring; so you can't be judging on wrestling skills. In all honesty, people go on about the MCMG but outside of the ring i don't have any interest in them because they aren't entertaining or captivating. Great in-ring though. It's wise to mix experience and star power with the younger talents you are building the company around and BOTH are equally important.
Great sports teams usually have a perfect mix of youth and experience because it helps the youngsters during the learning process.
@sinliner spot on mate.