First, you can't put contracts aside when you are rebuilding (or any other time). They are hugely important, and overpaying for one spot/mediocre talent can dramatically alter your ability to fill others.
Secondly, Heinrich might be able to be a roleplayer on a championship team...if he were surrounded by superstars. If the Lakers wanted to bring him in next year that would be a decent potential move. But if he's not surrounded by superstars, he has barely been able to hold down a starting job on a team that has bounced in and out of the playoff fringe as first round fodder. If he's 22 and cheap you could consider taking him and sitting on him for years waiting for your moment. But he's not special enough to be worth that trreatment. And at 28 with a big contract he's definitely not worth that treatment.
Take it from somebody who's been watching him from day 1. He is underrated still. He was a starting PG on a extremely young team that had no identity, and he was their best defender. He played through injuries, a coach that was hell bent on a his way or the highway system, and a discombobulated franchise that even after a decade of high draft picks was unable to develop any continuity or a bench. He'd be perfect for the Kings, as long as he's healthy. He's a leader to example, does not mouth off, will not embarrass you in the media, and will perform on the floor. He won't win you championships, but if you are a young and up coming team, you'd be crazy not to want him. Now, if you are a young and up coming team that has made idiotic moves monetary wise, we have a problem. So I do see your point. I just don't like how many see Kirk because of the contract and subsequent performances. He was injured and buried on the bench. Sefalosha was starting over him. Gordon was starting over him. When he has gotten time, he has produced. He can play the PG in this leauge, and be in the upper tier half.