SamyGO

Check if you have ArFix in mediaplayer and of cource check your network support.
Boot from external image means this and you never get boot it from USB you made. Here is missing info in merv07 manual about booting kernel from external source. So i guess you have 2008 firmware on board, identificator file shows 2009 firmware. It does no matter, you can delete Version.0 (or Version.1) file from /mtd_rwarea/ or change its content with ID to 2008 one. Do you have alternative firmware to switch to?

ok. flash 2008 over menu again and your 2010 is gone forever> After TV restarts, your alternative firmware will be 1008 and your actual firmware - 2008 with all benefits.

Yes, you re right. Re-flash patched firmware again to have patched in alternative firmware, because you can accidentaly activate it an get in trouble.

To have network you need copy rt73.ko (or rt2870sta.ko) - it depends from USB wifi dongle you have - some dongles use rt73, some rt2570sta and some rt2870sta.ko - you need only one driver.

Copy driver to /mtd_rwarea/modules and load it from there eg: Search for info:
http://forum.samygo.tv/viewtopic.php?f=2&t=956#p8001
http://forum.samygo.tv/viewtopic.php?f=6&t=577

and off course use search function:
use not internal search, but google widget on http://www.samygo.tv

All required modules are in samygo-all-extensions.

Do not know why do you have 2010 in alternative fw, but if you flashed 2008 from menu twice (normal fw upgrade procedure, not step 3), you should`n have 2010 in menu.
It does not matter, you can leave it as is, but remember - if you activate it, you need do whole job from beginning

Yes, to have your current fw as alternative you have to flash from menu it again. After this you have both - current and alternative 2008 patched.
Step2 is needed just for restore u-boot.