Recover/install Win7 onto multi-boot system - too many primary partitions?

Question

I have a few questions:  (first a background question, and then I'll get to the heart of the issue)
First, on a new laptop with factory installed Win7, I see there are 3 primary partitions - a 1.5GB "MBR-0", a ~10GB recovery partition, and the main installation partition.  What is the 1.5GB one for, and what's on it?  An MBR certainly doesn't need 1.5GB.  Does Win7 create that, or is that something unique for Toshiba?
If I'm using a 3rd party boot-manager (BootitNG via an EMBR on its own partition), can I just wipe that 1.5GB partition?   And, can the recovery installation be set up to create the Toshiba-Win7 recovery partition (and that 1.5GB one) as extended volumes within the Win7 primary partition, and not to make them as its own new primary partition?
And now to the main problem:  (the gist of it is, how many partitions will the Win7 recovery disks create? and can I customize it?)
I have a new toshiba c650 laptop that came with Win7 installed.  I created the one-time recovery DVDs first thing (it made 4 of them - Disk 1,2,3, and "64-bit environment").
I then wanted to set up a multi-boot system between Win7, and 2 instances of XP (one of which is a fresh install, the other being an image backup off a computer that died). I want each OS on its own primary partition, where each only sees/knows of itself.  Also, I'll have one small, 50MB primary partition for the boot-manager program.
Of course, a drive can only have 4 primary partitions (if working with standard tools like fdisk, etc).  To get around that (if needed), my boot-manager program will support as many primary partitions as I want, provided I use only it alone to manage/create my partitions.
Skipping the details, here's what I have now:  I wiped the hard drive, except for that 1.5GB MBR-0 partitition, for now, till I find what it is.  (Since XP doesn't recognize Win7, using XP's install cd would overwrite the factory Win7 installation, so I installed XP first on its own primary partition - and it's working fine).  I have the boot manager program on a second primary partition.  I then created 2 more primary partitions - one to place the XP-drive-image into, and one to install Win7.  So, the entire drive is now fully utilized and partitioned.
But here's the problem...
starting with the boot manager program, I'm pointing to boot from the empty Win-7 partition, which upon finding no OS, will cue it to boot from the DVD, and go on about its installation business.  So far so good.  At this point, Win7 will only "see" the empty partition reserved for it.  However, if Win7 tries to create an extra 1 or 2 new primary partitions (like how it came from the factory), the drive will end up with 6 primary partitions - not good.  So, my XP partitions would likely get overwritten. 
Having 6 primary partitions wouldn't be a problem, as long as I create/manage them only with the boot manager - but in this case the Win7 installation would likely create them during installation instead. If I pre-create those partitions (the 1.5GB one, and the 10GB one) with the boot manager, can I point Win7 during the installation to utilize those?  How?
One more side note:   When I'm in XP now, XP only "sees" it's own partition, but still senses that there's more room on the drive - it just considers it all as unallocated space.  I'm guessing Win7 would do the same thing?  And if it does, I'm worried it would start sticking its own new partitions there into what it "sees" as "unallocated space", even though my other partitions are there.
If you made it through this longwinded mess, thanks for what help you can provide!  How should I get Win7 on there, without damaging the existing partitions?

Answer 1

Ok, so I finally got it all to work. 
In case anyone else runs into this question where you have to use the Toshiba recovery DVDs to reinstall Windows 7, without damaging other existant partitions, here's the trick:  You have to pre-create an NTFS primary partition at the very front of the disk (1st primary partition), make it at least 20GB (preferably more, since this will be where you run Windows7 - unless you also later create another partition solely for data/programs/etc). Then during the recovery, select the option to keep current partitioning intact.  Everything will be placed in that first partition alone (the contents of which which the Win7 setup will erase), and the rest of your disk will be fine. 
If you have other partitions already there, and on the rest of the disk, you'll have to first resize the existing partitions to create enough room for this new 1st primary partition.  Then you'll have to shift or slide the current partitions up toward the back end of the disk (with 3rd party software). I also deleted the 1.5GB partition originally at the front of the disk (it's the startup repair partition, I learned), and I had previously deleted the 10GB recovery partition that came factory-placed at the back end of the disk. 
The XP-partition I already had on the disk is tested and working fine, and wasn't touched at all by the Windows7 recovery installation.  Installing additional XP-images or other OS's should be simple enough now.