how to install windows 7 on macbook pro using bootcamp

The capability manifests, but the functionality is not there.

I'm willing to bet that the performance problems the OP is having relates to the fact that a straight EFI install on a modern MBP 'enables' (for lack of a better word) automatic graphic switching. Macs are in something of a no-man's land in this regard, as they have neither an old-school BIOS or modern UEFI of recent Windows-based notebooks. A Mac's hardware is no different than a comparable Windows machine, but the EFI/BIOS/Firmware is. That's because it can create issues the OP is having. If you had carefully read what I wrote, I merely said that doing the install on a blank drive wasn't a good idea. If leaving that amount of space for OS X is too much of a hassle, then you have three options: 1) Get a bigger hard drive, 2) Replace your optical drive with a hard drive for more storage, or 3) do what you should have done in the first place and buy a Windows notebook. Boot Camp puts Windows as the primary startup disk by default, so it would be exactly like having an EFI installation anyway. 20 GB is plenty and you could get away with even less if you remove the hibernation file. It's best to leave a small partition for OS X and use Boot Camp for Windows. Incidentally, running an EFI-only install of Windows isn't a good idea. And if you actually read some of the posts on this and other Mac forums you will see that perceived build quality is just a bunch of hype, in my opinion. The hardware is the same and as to the OPs perceived better built quality I personally do not see it. In the end if you are going to run Windows on a computer by itself then you really should not buy a Mac. Pop the Win 7 DVD in the DVD drive and restart. No need for any Boot loaders or Hack Boot system.

you can't even change the OS X partition otherwise Windows would boot

You can only have one Windows partition and if you fool with it at all Windows will no longer boot. The problem with leaving OS X installed is then you are really limited with what you can do with the drive. That may of been true with Windows XP but not anymore. There is no real need to leave OS X on the Mac if you don't want to, especially with Win 7 or 8.

How to install windows 7 on macbook pro using bootcamp