There are too many PE and I don't exactly know which to choose or 'master' on using BartPE, LiveXP, Win7PE, WinPE 3.0.
In reply to your original Post #1. My vote would be WinPE 3. My reasons are:
1. XP is hard to get to work on modern AHCI and SATA systems without adding extra drivers and does not work with USB drives as boot devices without a lot of tweaking.
2. XP drivers will no longer be available from manufacturers for new h/w platforms
3. Vista drivers will no longer be available from manufacturers for new h/w platforms
4. WinPE 3 supports most 'old' h/w with built in drivers. Extra drivers can be easily added.
5. WinPE 3 is fully supported by MS and used by OEMs for factory OS installation and testing
re. drivers, I am already seeing OEMs not providing Vista drivers for new h/w. Why would they when Win7 is the shipping OS? XP is still used in the corporate world and so, at least in 'office' systems, XP drivers may be available for at least a year or so for new h/w - but on consumers devices (e.g. netbooks) I also see them dropping XP support. This just leaves us with Win 7 drivers - unless someone starts writing XP drivers in their spare time (XPinux group anyone???).
So you could spend months getting to grips with XP based OS's and spend a while getting to know all of the workarounds, only to find you cannot get it to work on new h/w. What about new hardware features like USB3, removal of GateA20 in new Intel chipsets, new SSD drives and TRIM function, EFI, multi-touch, etc. on XP - how easy will it be to add support for these???