Hi,
some answers to your questions :
1. YES - You can copy DMG/USB to a internal/external partition on HD, place Chameleon and EXTRA_Lion on it and run Lion Installation from it . (it was my first OSX Lion installation attempt )
2. smbios.plist is necessary to bypass OSX Lion installation Check.
After installed Lion, you can delete it ( BTW i don't recommend it )
3. Extra_lion.pkg have all kext minimum necessaries to install Lion. You can experiment if you like to find your Kexts
4. I use VoodooHDA.kext , but it depends on your HW .
DSDT patching don't works for me.. Do as you like ...
5. As above, it depends on your HW.
i use Intel1000e.kext patched for my network card.
BTW you need a Kext that works on 64bit on Lion
look on
www.Kexts.com
I hope this will help you ...
Cheers
PippoX0