How should i go about overclocking E5200

here's the components that i have:

CPU: Intel Pentium E5200 @ 2.5Ghz (Idle @ 24C/System @ 35C)
MB: ASUS P5Q-E
RAM: Mushkin XP2 8000 Redline 4GB Kit w/ OCZ XTC Cooler
GPU: Sapphire 512MB HD 4870 Toxic Edition (820MHz/1200MHz Idle @ 52C/36% Fan Speed) is this ok?!?
HDD: Seagate Barracuda 7200.12 500GB x 2 Running RAID 0
HSF: Scythe Orochi 10 w/ Scythe S-Flex 120mm 1600rpm Fan
PSU: Anteq 500 Basiq Power
Case: XClio A380PLUS w/ Scythe 120mm x 38mm 3000rpm Fan for Exhaust

so after deciding i wanna run RAID, i kept the ASUS P5Q-E instead of the GIGABYTE GA-EP45-UD3L (still trying to sell it btw), but while i was using the EP45, from the EasyTune 6, it was stable @ 2.97GHz, then i tried playing around with the settings, no luck on further increase....now that i've switched back to the P5Q-E, i tried just playing around with the FSB and vCore, it won't even boot up at all at any settings, so am i doing something wrong? and how should i go about overclocking the RAM (cuz the board only recognize it as a pair of 800MHz RAM)?

what's the max voltage that i can use on the E5200/RAM? 1.5625v CPU/2.1v RAM?

should i just leave it as AUTO for settings like: CPU/NB GTL Voltage Reference,CPU PLL Voltage, FSB Termination Voltage, NB SB Voltage, NB FSB, etc.

what are people's max stable overclock speed from the components that i have? (i saw some people online can reach over 4GHz just on air-cooled)

should i just grab the ASUS P5Q-Pro Turbo for easier overclocking? would it make a difference since they are just the same series w/ different add-ons?

and is Dual GB LAN useless in a home setting? (i heard in order to take advantage to it, you gotta have 2 ISP lines)

+1. Start in the BIOS and go slow, don't jump into a large overclock and expect it to be fully stable. Some chips are lucky some aren't. But usually the E5200 is a great overclocker.

Up the FSB slowly? WTF. Go straight to 250 then 275 then 300. 275 should be doable on stock volts.