iPhone G3 Battery and Performance Issues 3G

I have a 16GB iPhone G3 (OS 3.1.2). Its only about 6 months old though it is the 4th iPhone G3 Ive had since Sept 08. The others have been replaced by Apple for battery failure, modem failure and inability to stay connected to a charging device even when physically still attached to the charger.
I have over 8GB of free space, Push is turned off, WiFI is turned off 99% of the time, and I dont have any major apps that might use up a lot of the battery or CPU cycles.
Ever since the 3.0 or 3.1 update:
My battery performance is only about 1/3 of its previous performance. Ive charged it from two different Macs as well as the car charger but still get horrible horrible battery life. It has simply made the device undependable while I am away from a charger.
My iPhone is regularly unresponsive. Sometimes for only 3 - 5 seconds, other times for up to 30 - 60 seconds. This happens whether or not the iPod is playing, whether or not Mail is downloading and even when nothing else at all is being used. This happens repeatedly throughout the day.
Many times all the input events are buffered so it tries to perform them all once when the phone comes out of its stupor. Other times nothing at all happens once it revives.
Several times a week I need to power it off just to get it to work again.
A few times a week applications dont load or quit properly: - Mail may load the header & footers but not the body of the app. None of the software controls work. Quitting the app and relaunching it does not resolve the problem - only a shutdown/restart does.
- The green Return to Call bar will stick around after a call is over and can only be removed by placing another call, leaving the phone app, touching the green bar to return to the call and then ending the call.
- Maps loads the header & footer and a portion of the screen. None of the software controls work. Quitting the app and relaunching it sometimes resolves the problem but not always.
- After some calls end the entire screen appears disabled and the Home button doesnt work. This usually requires a restart to correct.
- The iPod will stop or stutter while some other process is running such as checking for mail or loading another app. What good is an iPod that cant play dependably while I use the device for other things?
- I drop so many calls that if calls were passes my iPhone could play for the NY Knicks. I suspect its probably an AT&T coverage issue though I would hope the NYC metro area would have better coverage than this.
Bluetooth just turns off all by itself. I have to go into the Settings and turn bluetooth back on. This happens with all three of the bluetooth headsets that I use.
~
The phone is acting like it occasionally has a race condition that is eating up the CPU cycles. It is so often and so unpredictable that I cannot pinpoint what the cause is.
All this is very frustrating and tempting me to revert back to version 2 of the OS. Im not happy at the thought of losing Copy & Paste but I certainly lose more time waiting for the device to decide to gets its act together than I would re-typing everything I copy & paste.
Ive considered going back to the Apple store again for another replacement but I have little confidence that #5 will be my lucky iPhone. Im not sure why the quality has been so un-apple like but Im 0 - 4 with iPhones even though I treat them with care. Since this dismal performance appears to coincide with either the 3.0 or 3.1 update Im not convinced its even a hardware problem this time.
As much as I depend on the phone & e-mail to run my business I cant rely on this iPhone at all.
James
iPhone G3 iPhone OS 3.1.2 16 GB