It is not a problem but it is normal. Heating issues doesnt mean that the phone has problem. Since it worked so hard (and even we tweak it so much), normal to be below 50 degrees. Normal will be 33 (for mine with overclock 1400 mhz). If you undervolt I believe it will reduce some heat. Normal playing around is below 40.
Adjust brightness and you should be fine. Also, reduce refresh interval to increase juice. Install Juice Defender (I got to admit that the setting need some serious time to slowly adjust to your liking) and you should be fine.

Some roms are said to give better battery life but self preference I guess. KG6 seems nice for me.

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Added on August 3, 2011, 2:06 pm

My dear...

1. To have Google Navigation activated, check page one
2. Are they talking about black market? Forum not able to talk about black market stuffs. As far as I know Papago is chargeable.

My advise is: Use Google find if you want to know