What Would Happen If Ted Turner Purchased Tna And Decided To Get Back Into The Wrestling Business?

I think at this point it wouldn't make much difference. Turner is not in charge of what gets put on the air on the stations he established, anymore. So, it's very doubtful he could persuade his bosses to bring TNA aboard.
Turner, of course, would have some influence with Spike TV's management and could probably get more advertisement for TNA, but Spike does a decent job advertising TNA as it is.
Turner's money could help TNA pay more to attract big stars from the WWE but it would have to be a considerable amount. I don't think just a pay raise will cause the really big names in the WWE to make the jump, though; most people consider TNA "small potatoes" compared to the WWE. And the WWE can be a springboard to other forms of entertainment. TNA doesn't really have that.
Turner's money could make TNA a bigger production on the road, but in this economy even the WWE has had to cut down the number of house shows they do. TNA is nearly on-par with the WWE in their TV and PPV productions, so extra cash won't make much difference there.
Really, the only way I could see having Ted Turner on-board would be to have TNA moved to TBS. It's a basic cable channel, everybody gets TBS. But Turner doesn't call the shots as far as programming goes, anymore. The extra cash he would provide would help the company (who can't use extra cash?) but if Turner can no longer provide a larger "home" for TNA, then he really wouldn't make any difference.