I don't know about a mid season tournament, but I do like the idea of an NIT type tournament for the teams who don't make the playoffs at the end of the season. I'm sure something like that will be frown upon and "clowned" by some fans but, I think over time, it will win people over..Especially if the incentive is worth it (more pingpong balls in draft, an extra first round pick or extra $$ cap space for the following year).
I don't believe reseeding is necessary but I wouldn't be opposed to something that. I would like the NBA to finally implement a REAL minor league system.
Also, not a fan of "sign and trades". I know they benefit both teams, and I am all for players taking having control of their careers, but removing this "loophole" will force teams and players to show their true intentions early on and confirm their commitment to each other