No chance the Rockets do this, since they can just sign him in the offseason. As someone who has closely followed Morey's moves throughout his Rockets career, I can say for certain that he's not going to move Lin. Oh, Morey will certainly move Lin for a star player, but that's unlikely given the current NBA landscape and Lin's production.
The Rockets really like his talent level. I think it will be tough for them to trade him now for fair value until he starts playing in D-League. That said, he may be a bad fit with Harden.
I don't know how you guys figure Royce White will be traded. The only way I can see him being traded if he's included in a bigger deal to make salaries match. His trade value couldn't possibly be lower. I can't imagine there is a team in the league that would even give up a late 2nd round pick for him right now.
Salary cap. Milsap only makes 8 million this season. If the Rockets could get Milsap that cheaply, they would still have quite a lot to offer to get another player with all the expiring contracts, cap space, and players still playing on their rookie contract. In offseason, Rockets would use bird rights to go over cap to sign Milsap and any expirings left on their team that they want. Rockets would have to relinquish rights to lots of guys in offseason to sign Milsap, etc. Bird rights to guys like Douglas, Cook have value to certain teams that are over the cap as they are better than vets at the minimum.
To prevent teams from doing what you say, there's a cap hold for FAs not signed and not renounced by the team. So the Rockets can't do what you're proposing. I think for Millsap on $8mil salary, his cap hold would be 150% or $12mil. So you can't just, say, trade for Millsap, sign Iguodala in the offseason, and then re-sign Millsap.
This is the first year I'm not really anxious for a trade (thanks to the Harden trade and FA signings). My guess is we'll take it as easy as we did last season so I won't be holding my breath for something major (but who am I kidding, I know that will change once the deadline approaches).
I can understand this, but I can say you're missing out on a lot of the joy of following the sport. Investing in a team means investing interest in all aspects of the game, not just what happens with players and on the court, but the building process, competing with other teams in the financial economy of the nba, becoming a fan of the coaches and front office, etc. Routing for your team through all that makes the sport so much more fun and interesting.