The most important thing TNA (or any group for that matter) can do is to be as different from the WWE as possible.
Different in ring style, no backstage "why is there a camera here for out secret conversation" segments, no on screen authority figures, etc. All of these things just make you look like WWE-lite. Be bold and do something different.
When biss started Inspire, he didn't copy Anarchy. His promotion has a completely different tone & feel. He runs his shows in an art house as opposed to a rowdy bar, he uses a lot of different talent, he doesn't do 4 or 5 hours shows, he has stayed away from women's matches, etc. Why the fuck would anybody go to an Inspire show if it was just a junior version of the already established promotion that runs across town? I see many of the same faces at both shows, because they are getting something different at each one.
I don't think the brand damage is impossible to overcome. A fresh, unique product that focuses on the things WWE does not emphasize, with smart, logical booking & fresh stars would appeal to wrestling fans and might just bring back some people who handwaved wrestling when WCW went under. I don't think it would matter if you call it TNA or Impact Wrestling or Inspire Pro Wrestling or NWA or United Wrestling Association.
I agree with about 90% of that. Two things though. I did like WCW's take on an authority figure. Not some cartoonish heel or over the top comedic face, but just an older wrestler who plays the straightman and occasionally off-sets heels being heels. Kinda off-topic, because I agree that they shouldn't go that route. Just saying it can be done in a way that I don't think it stupid and takes away from the product the way....say, Vickie Guerrero did.
Th other thing is, I think a LOT of the old WCW fans have seen or at least heard of TNA and haven't caught on or outright hated the product. So to have that same name just makes it easier to gloss over it, ESPECIALLY on your cable or satellite guide. Even if someone recommends it to you, you're likely to be set in that mindset that "Seen it, don't like it." Which is not to say that a new name would get people viewing, but why put yourself behind the 8-ball if you don't have to?