1) Could be done. I would suggest that you can make your own custom colors at 20k, and ever 1k qi you unlock a new color on your wheel. Similar to the concept in the game Rainbow Vegas. Then once you hit 50k qi, you are able to make any color possible.

2) This is definitely doable. A few objects can and should be made for the old players. It only makes sense to reward hard workers with a small token or appreciation. An armband for 20k qi would not be so bad, or if you had something else in mind, pitch the idea.

3) Now, this is a stretch. You out of all people know that adding tc boosters to accounts could pose a problem. Instead of this, we could propose some sort of reward system like you can get tokens towards a certain item. If you are a custom belt, or higher, the only thing you will use the tc for is to sell. Usually you will have most of the stuff you want by those levels.

Overall this is a great idea and without a doubt, it should be implemented. For the 3d items, at every 10k qi after 20k, you should get a different unique 3d item. I fully support this, and it would give me something to strive for instead of aimlessly playing around. It would also be a lot better if these 3d items were not purchasable like the ST ones are now. Supported. You should try to get this idea pushed through.