Couple Issues

Issue 1, probably not getting as hot as you might think. Those of us who overclock frequently see our Droids get hot. I'm assuming you're running stock. Navigation problems? Yes, people have them from time to time.

Issue 2, it's a well known issue. Most of us experience it only once, I've seen a few people say they've seen it more then once.

 

Are you overclocked? If you are, you don't need all those clock cycles while using Nav, throttle back to 550-600mhz. Also, if you are charging while Navigating, that makes for more heat.

I've never had that battery indicator problem.

 

Both problems are related. I have suffered from this problem and at first I thought it was the gps antenna/chipset. Then I noticed that it wasnt truly getting hot because of the gps I mean it can get warm but not hot. What happens is that when you have the gps running and your charging the phone your in your car and a black metal phone attracts plenty of heat from the sun and causes the phone to overheat. I have noticed that moto's engineers have put a failsafe in that stops the phone from charging when it gets too hot. most likely to prevent damage to the charging circuit and or battery. My suggestion when this happens is keep it out of direct sunlight and you will be fine it will stop your phone from overheating which is also causing your phone to act retarded. most electronics do not operate correctly when they overheat. When it happened to me i took my phone out of the sun and when it got to a decent temperature unplugged my phone waited a few seconds and plugged it back in, then it charged fine . No need for a reboot.

 

I've noticed that the sun heats anything placed where I mount my Droid in my cars. Nothing to worry about unless the battery overheats.

Depends on what's causing your GPS issue. I've never had issues with random routes but others have certainly had problems with the directions given or the location of the destination.