well d430 and d620 intel have worked both great for me
but the d630 is more powerful machine just very finicky... crc has 3 of em and only 2 want to work.... the third one kp's all the time even when swapping hdd's from a working one to it. yet windows runs fine... they also all have the same bios. so go figure... weird no?
nope nothing special on 10.6.8 mostly kernel changes to prepare for lion... so just problems awaiting and higher temps... the last true snow leopard version is 10.6.7
have you tried using chameleon boot0md instead of boot0hfs you have the option in chameleon wizard works better for multi-boot environments i have lion and 7 on my d430 using that.
Yes you would have to replace the extra folder as the dsdt from the image is for d430 also you need to run the latest chameleon and make sure com.apple.boot.plist in extra is renamed to org.chameleon.Boot.plist with a capital B in boot as shown. Once it finally boots then you can install EDP to it and build for your machine. Hope that helps a bit.
make sure you have the latest chameleon and set your resolution in org.chameleon.Boot.plist use chameleon wizard as for networking you need your old networking kexts 10.6.8 updated them in s/l/e
delete all networks and devices and re install if not the networking plist needs to be deleted
also, if you don't have it, put EheternetBuiltIn=Yes
in you org.chameleon.boot.plist
justin d620 is a very different beast (it uses 945 chipset) then the d630 (uses 965 chipset) the closer match would be a d830 build wise. have you tested some of the other dsdt's on the forum for d630? and if you can please put the machine specs in your signature... makes it easier to remember what i'm dealing with...
your pic above is not a good sign.... sometimes you get that with a bad gpu especially nvidia are notorious for it they used to have a recall on it a few years back.