1) Most crashes are caused by operator error for not providing the maximum memory reservation for TomTom 6 to run. If you have 8 to 12MB free prior to launching TomTom 6, you will have a slim chance of crashing this program. So, try your best to move all programs / temporary files / mp3 / docs out of the TX main memory and move them or reinstall them into SD card instead to maximize the free up your main memory.
Slow, yes, this is true but it is not "extremely" slow. It is technically slightly slower than previous version 5 it replaces but not so slow to a point it that you cannot use it at all.
2) Let me try to clarify this. There are two scenariors to this questions.
a) Making a phone call while TT6 is already running: To make a phone call to a contact stored on your Palm device, you must first switch (not Exit / Quit TomTom 6) to the "Phone Dialing Screen" or any "Voice Dail" software you may have on the Treo 650 / 680 / 700p.
b) Receicing a phone call while TT6 is already running:
So, only scenarior B fits into the TomTom.com advertised feature (see the statement below) on their product page. Hope this is clear. In scenarior A, you must leave / switch away from TomTom 6 Navigator software before making a phone call. Unfortunately this is a limitation due to the Palm Operating System, not TomTom 6 software. Palm devices can only handle on process at a time. The easy call handling is built into the application meaning if a call comes through, Navigator knows how to handle the call. You will not be able to make a call while the program is running but you can receive them. When a phone call comes in, the voice instructions will mute however you will still be able to see the route instructions to know where you are going.
Source: http://www.tomtom.com/products/features.php?ID=286&Category=2&Lid=4 (under Call handling section)
"Easy call handling: On-screen instructions remain visible while making phonecalls or receiving SMS messages. "
3) Yes, pretty sure and we have help a number of customers setup their Palm TX.
4) I repeat. SKU 575 for Add on cable for charging Treo 650 / 700w / T5 / LifeStyle / TX / E2 and OnCourse SiRF Star III or Globalsat BT-338 Bluetooth GPS Receiver will only work with either of the following GPS receiver: (All pictures below are clickable and will open up a new window
<== either one ==> 
So, you here is your shopping list:
a)

and
b)
