There are already regrets on some of those 2016 contracts. And you can only get, what's out there. So for a guy, who was almost out of the league last summer, I don't think, there's a lot. As of right now only 6 teams are guaranteed to operate in cap space mode: Sixers, Nets, Nuggets, Suns, Celtics, Wolves. Of course, there are options and non-guarantees, but quite a few options are for players, who expect increases. Don't see anything above MLE ($8.4m) available, and since MLE must be at least 3years, I expect most of that money being non-guaranteed.
Johnson was fine in Toronto at SF on both ends, especially when he was allowed to make plays: off the ball players, who can't shoot, can only do so much to not hurt their team offensively, especially when they share the floor with Bismack Biyombo. This year results suggest he might finally be able to shoot, which is often the case with ballhandlers, who were bricklayers early in their careers. Plus Kings could use some additional ballhandling. Positional versatility of filling both forward positions is a nice bonus.
http://www.sactownroyalty.com/2014/12/3/7325551/James-Johnson-reflects-on-Sacramento
Those weren't even PDA times, so you could suggest, that Vivek was part of the problem. His year was during Vodka brothers.
P.S. Reading commentary on Detroit struggles, it looks like Pistons are really missing Tolliver in the locker room. I'm almost sure, Kings should keep him, now that he looks decent off the bench.