Are you saying the software and processing circuits are all in the DMD chip
Would I need to do anything else than getting a 73833 (the 3D chip) and replace it?
No. I am saying that the white dot problem is just a defective DMD chip. TI had a bad run of them in your model year, and Mits has been known for helping out with the cost of replacement.
The 3D issue is a processing issue, which is on an entirely different chassis. If you want 3D, you are better off getting a newer TV. Prices have come down, and you can get a new 73" Mitsubishi for under $1600.
"The wise understand by themselves; fools follow thereports of others"-Tibetan Proverb