Curious why you pair to an external GPS with your phone. I get locks in about 10 seconds with the built in GPS.
I am in the United States. I use the Fone Fanatics Cab that sets it to use the nokia.supl thing. It sets a few other AT&T specif things. There are other versions for other carriers.
If you need to pair to an external GPS, you might as well just buy a seperate GPS unit. I picked up a TomTom 125 on Black Friday for $59. I like the audible turn by turn directions and it has a larger screen. Uses nice big fonts and shows my speed next to the speed limit.
About the 4000 messages you have. Back them up. Keep them on your computer. Don't restore them all. If you use PIM backup, uncheck binary. You can then import it into excel with ; as the seperator.
You can then restore, but delete some off of your phone, maybe keep a months worth or something. Large numbers of text messages do cause problems. It's been mentioned in the thread a few times, but not super often, because most people don't have 4000 messages.
Text messages can be backed up, altered, and then restored, so your text message log is not evidence of any commitments. They are only for your reference.
I am on the 28014 Christmas theme and have found it to be very stable.
UC or Sashime can add registry customizations in.
There is a free cab file creator on xda somewhere that you can also create registry entries with. It's called QuickCab-2.0
Only the cab is required to put at least 1 file on your system.
Just have it put a small txt file in your temp folder.
I use Visual Studio 2008 Professional to make my cabs. It has the same limitation though.