Actually, you waste a great deal of time fucking around to make the deal as best as you can. Both sides do. It's why they get paid lots of money, and trades aren't done by fans.
And you're right, time isn't on our side, but most other teams aren't going to rush because we're trying to re-sign LeBron. They'd rather get the deal they'd be happy with.
Not all expirings are created equal. They are all different. Wally's would be the worst one a team could get. And teams don't try to stack expiring deals for next summer this summer. It's better to field a semi-competitive team until the trade deadline to sell tickets to your games in the meantime, and do a salary dump at the trade deadline. The only expiring a team would want this summer is one built like Delonte's. So his is valuable now.
Your last paragraph is bizzare. It's all wrong. I don't really understand what you were talking about with major player's on-court play being useless, but you do understand that A) Wally's contract could not be traded next off-season and B) Any team that picks up expiring contracts isn't doing it to trade them to someone else, right?
EDIT:
Hedo is a guy who is over-paid, but can still be a very good player. The Raptors would be able to trade him with Bosh in a s&t very easily, but at the very least, they'd be able to move Hedo straight up for a much better deal than Wally.
But what you get for Hedo in a Bosh S&T is an expiring contract can you see where this is going.