Archie, you easily could have said in 1 sentence: The treo doesn't support proximity detection, SMS, callthrough, and caller ID events (and, to add to your list, phone status info). Salling clicker was primarily written as a bluetooth remote control, and those functions work well. No need for the repetitive (might I add -- DOUBLE -- post.)
And it is a question of implimentation.
Why would they enable other bluetooth tasks, and leave out several (obviously crossover linked) features. What do thay have to gain by disabling sms or caller ID OSX specific functions??? These are obvious (to me, a former programmer) bugs that they never knew about or never had time to tackle. I don't mean to be standing up so much for PalmOne -- but people sound like they are doing this on purpose. If anything, it's just non-complete integration.
Now if you want to yell about Sprint or Verizon castrating bluetooth to make money through calling plans or Get It Now, then please feel free to b.itch the house down.