Well you must not have paid much attention in school lol, this should be second-nature if your in IT as I'm just about to graduate this semester from Seneca@York College in Ontario
Not to burst your bubble or anything, but I've been booting Windows 7 from GUID for over 5 years now, when you install windows to a GUID partition it must be synchronized with the MBR (GPTSYNC), there are several tutorials online, not to mention MacBooks Boot Camp partitions usually reside on the GPT. It's not hard to get windows to boot especially when were not even interested in using the Windows Boot Manager. Chameleon does the job just fine.
Err, you have a lot of loose ends here lol... I do have an MBR boot of Leopard enabled on my 750GB drive, (500 GB PART formatted as HFS+), I unfortunately can't work the boot loader as easily as with a USB but since I have my GUID SSD booting to Chameleon, it doesn't matter. So yes, you can boot mac from the MBR, again, refer to Google for tutorials if your lost, it's fairly simple with a hackintosh as making a Recursive copy of the contents to an already partitioned HFS+ part on an MBR will allow chameleon to boot from the drive.
Now I've read a ton of reports about the A12 bios not booting from GPT... if that's true, that's sucks. I suggest upgrading to the A14... I have a FULLY functioning triple boot with all my original drivers restored (turns out that Dell shipped us a laptop with the wrong driver CDs, and what's worse? they don't have the drivers on there support site.. luckily google led me to a forum who a fellow who was clever enough to back them up before wiping the drive)
The BIOS does not limit us to "microsoft" in anyway, A01-A08 only supported FAT32 booting which has skyrocketed in directions I can't explain but since A09+, Dell has always been able to boot from GUID (I also own an m1570... or 1750?, it's an old duo-core with fingerprint reader.. it's currently booting my Plex Media Server just fine from GUID)
Alas, did you have any success with Dell? As far as I know, Customer support sucks. If they offered you anything, let me know... I'd love to swindle something out of this haha...
I see you really do not have much C++ experience, lol, I didn't particularly find anything different in your DSDT.. that matters, anyway, haha sorry.... but I will be working on one to "detect our GT 555M 3GB memory" although of course it will only be a statistic, not an actual graphics driver. Uh as for your comment about the 4 Memory slots, I hope you aren't referring to the DIMM slots on your Mac, as you do realize, we are hacking the OS.. and they always show 4 DIMM's unless you configure it manually, but to be honest... it functions better thinking there's 4 DIMM slots as most high performance Macs do have 4 DIMMs and not any of there laptops and reconfiguring the dsdt or smbios to display only 2 would be a hassle, (it would be a crazy trial and error process as I believe no one has done it or cared to yet).
I plan on creating the installation guide (extensive guide describing single/dual/or triple booting) by mid february so if you need any help, just message me, I'll also be describing how to make a functional Recovery Disk as well as solving any boot problems, I'll also refer others to the Nvidia drivers that are ironically not on Nvidia or Dell's site for our GPU.
As for the DSDT and SSDT... I will edit the nicely compiled version that Steve left us for our model as well as correcting the differences between our SSDT so hopefully we can have a fully functioning sleep... apparently it's working splendidly on his model... I don't know if your lucky enough to have it functioning currently? but that may change once you boot from the HDD. I plan to have this finished by April, sorry, I'm going to be really busy this semester.
There's no reason to use USB3.0 to boot, it's a hell of a problem, not only does it occasional crash just from being a modified driver but the speed difference is unnecessary and injecting a kext to allow booting your install or drive should just scream out bad news to you.
As far the Chimera standalone installer... if you can't boot from the GPT than it isn't doing anything. don't use the standalone, it uses a newer revision and will only support your kexts in boot but will not boot your system.. Install Chimera from MultiBeast 4.2.1 and take note of the Revision if it matters to you. Replace the chimera.boot.plist with Steve's, and add his legacy apple.boot.playlist just in case you need to boot into leopard again in the future. Add the DSDT if not there already... if you get KPs, remove the SSDT
The Realtek ethernet driver has NOT been customized (no drivers will ever be) for our dell so I wouldn't suggest using whichever your using, just update to the latest from multi beast.
Steve's DSDT allows for the "QuickSet" keys to partial function so FN + F2 toggles your Bluetooth Adapter. The touchpad toggle likely doesn't work, and the monitor detection (F1) is key when having external connectivity issues. If you didn't get the TV Tuner adapter, you can get a WiFi PCI card in it's place and have both wifi cards unfortunately I have to use a USB version as I purchased and use the TV Tuner in Windows.
As you've probably noticed... It's extremely difficult to get into the Lion installer on first try... the RAM chip HAS to be removed unfortunately but I will post a way which allows you to boot from a Recovery Disk without having to remove your extra RAM although it's super easy, it's still tedious.. especially if your just doing a disk repair or something of the sort (time machine restore?)... and yah, I think that's it haha
God I hope Graphics Support comes from Nvidia but otherwise I know exactly how everything works on our machine, so if you have any specific questions or requests for support... (obviously I'm working on these damn brightness keys but since our GPU is being shafted, the Intel HD3000 definitely doesn't have brightness control so I'm thinking my chances are none to slimmer than none) but I've almost got the 3 touch keyboard shortcuts working (I don't actually know what they're for in windows haha)... try setting the [Gears] key to your System Preferences... the hot key is OPTION (Windows Key) + V... if you go to System Preferences.../Keyboard/Shortcuts/Add custom at the bottom... Type "System Preferences..." and assign it to WIN+V, when you reboot.. it should function as a nice system control panel key