Why do bluetooth Trackpad and wired USB drivers conflict 10.6.7

It seems Apple's implementation of Bluetooth Trackpad is incompatible with 3rd party wired mouse drivers, which have been around and continuously developed since OS9 days. The odd thing is that what breaks is the bluetooth device discovery and pairing process via either the Bluetooth or Trackpad Preference panes. Also bizare is the interaction with wired usb mouse drivers that do not attempt to pair with bluetooth devices. I could understand the failed cursor control on its own, but bluetooth vs USB at the recognition of device level is a weird failure, as it is kind of like my car failing to drive because I installed after market fluffy seat covers.

I am rue to start a forum on the new Trackpad that I purchased June 2011, tried to implement under 10.6.7 (updated from a 10.6.0 Retail disk), but I've returned it for credit as unfit for purpose, despite 12 hours talking to AppleCare, and about the same searching the community and knowledge base. I did get it to work after a fashion by retro-installing (via pacifier) much of the bluetooth and bezelservices components from the 10.6.5 combo update.dmg. I had removed all vestiges of third party software: USB Overdrive, Kensington, Logitech and a few others I tried sequentially with multiple clean installs.

This partial solution to initialize the Trackpad although eventually gaining curse control over the Trackpad via the Trackpad pane (broken in every instance of third party software), failed to resolve the additional issues of non smooth Trackpad cursor (even with the eventually found Tackpad update - this is NOT installed automatically via the 10.6.7 Combo Update!!!); and any use of the Trackpad rendered my wired mice largely unserviceable - both Apple and Logitech. without the Trackpad these mice functioned perfectly - although 3rd party software is necessary to provide sufficient cursor acceleration across my large screen (1920x1080).

Granted third party drivers may use odd implementation methods, but all of them? Either Apple should provide standardised frameworks and preference panes that can recognise, accept and utilise industry standard button and scroll axis inputs. I had hoped the advent of the Apple mighty multi-button mouse would give me sufficient control to use the Apple pref pane to assign <command-Click> to my thumb button, and <option-click> to the wheel buton, but unfortunately I had to revert to USB Overdrive to do so. Not even the mighty mouse can accept these basic button assignments.

I am interested to get insight from others - particularly knowledgeable developers -