That still wouldn't explain why it will boot with safe boot, and if it's capable of running 10.6 at all, that automatically means it's an Intel based system so the maximum age would be around 5 years old for the unit. It would also make running a PPC based version of Mac OS (X) a bit tricky. Also, pretty much every x86 based Mac, should be capable of running 10.6, save the 2011 refreshes and beyond where it starts getting a bit iffy due to hardware support.
One of the things Safe Boot does, is disable hardware acceleration of the video, meaning all the GPU is doing is just passing along the signal the CPU processed for it. Which is roughly equivalent to what it's doing before the GUI loads, when it's using EFI level drawing primitives to paint directly to the screen. However, once the OS loads and starts making use of the 3D functions, as Aqua is essentially a giant OpenGL program, you run into problems.
The 4GB mentioned for OS X, is the amount of HDD space needed for a minimal install, not the RAM.
Finally, the speed of the memory bus would have nothing to do with whether or not the OS would boot. It would affect the speed of booting, but not booting itself. As long as the data can get from one part of the computer to the other, the speed is generally irrelevant. I have no earthly idea where the whole scripting thing came from, so I'm just going to write it off as you having absolutely no concept of how software development actually works, and just leave it at that.
Now before we start in with your usual bit of whining because someone pointed out that you posted a bunch of nonsense, consider that maybe a better use of your time would be actually learning what you're talking about instead of whining because someone pointed out that you posted a bunch of nonsense. It would be one thing if you just had a few minor errors in what you said, but there are several major glaring issues here.
1: The OP said MacBook, automatically making it an x86 unit, since Apple rebranded everything with the switch to x86 CPUs. The PowerBook became the MacBook Pro, and the iBook G4 became the MacBook.
2: Mac OS X 10.6 was the first x86 only release so the only way to get it to run short of a VM would be if the OP had an x86 system, like a MacBook.
3: Mac OS 9 was PPC only, as was Mac OS X 10.0-10.3. Mac OS X 10.4 was the first release capable of running on x86 hardware, though it was only distributed in the form of OEM restore discs. So for all intents and purposes, 10.5 marked the official beginning and end of dual platform support in Mac OS X. Sure, if you were to go rifling through Apple's development servers you might be able to find a copy of 10.3 capable of running on x86, and it was probably used by the system designers for prototype units. Odds are if you ever tried using that version of 10.3, you'd quickly find out why it was never publicly released.
4: Apple stopped supporting Mac OS 9 around the time 10.4 came out, and as pointed out in #3, the unit would have to be a PPC system which would be ruled out by #1
That's just for your first paragraph.
You want to help out, great! However, that means actually knowing what you're talking about, and ideally not wasting the time of people, like myself, who have to come along and point out the numerous and grievous errors you're making lest someone actually are posting something that isn't utter nonsense. So I would suggest that you take all the energy you're building up to post some kind of scathing response for me, and channel that into actually learning a little about computers. Then, maybe the next time you post something, someone such as myself will not be forced to point out the numerous factual errors with what you say, because there won't be any grievous factual errors.