Power to Kemba Walker? Sorry that I pointed only him out but that is ridiculous.
Anyway, all of them have no word when it is about business. The owners decide about the cap and the contracts and if they decide not to pay for someone, they will not do it. No matter what those guys you mentioned want. In Cleveland LeBron's buddies get their big contracts to make him happy.
LeBron is the player in the league who has the highest Basketball IQ and understanding of the game so it is not a bad thing if he shares his thoughts with the coach and influences the team but no other player in the league would dare to put himself above the whole franchise. There are plenty who have problems with their coaches which is the case with thousands of athletes in all kinds of sports but there is a difference between those usual cases and a player who has so much power that he can basically pick the coach for himself and his team.
Considering Wiggins: I said that it is okay they made the decision to trade the future for today's stars to accompany James. But Love turns out to be the wrong guy and they should have known better about his skills and what he brings to the table. Turns out their "Big 3" is totally unbalanced and they have absolutely no chance against healthy Warriors or Spurs.
I know it is easy to say that now but it is almost impossible to force a championship.
There were to recent cases where forming a super team ended up with a championship: The Big 3 in Boston which would have never won a ring without Rondo turning it into a Big 4, a huge surprise for everyone and of course the super friends in Miami who were bragging about not losing any games at all but realized that they did not have enough pieces in their first season only to get saved by Ray Allen's miracle three pointer in their second finals.
Long story short: No matter the city or franchise history it is stupid and not healthy for the whole franchise to let a single player run the whole shit.