Well Windows needs to be on the primary partition of the harddrive (I think this is what you mean).
let's try to answer some stuff :
1. First install WindowsXP and then install Linspire (Linspire should detect the Windows XP installation and add it to the GRUB Bootloader, at least when you put them both on the same drive, I don't know about 2 drives but I guess it's the same). You can put Windows on the Primary master (C: drive in windows or hda in linux) and Linspire on the Primary slave (hdb).
2. Linux has problems with the NTFS filesystem (there is red support and limited write support, allthough I've heard writing to NTFS has improved a lot). What most people do is install windowsXP (I think you can't install XP onto a FAT/FAT32 partition) on NTFS and make a seperate partition (with partition magic, disk director, etc. etc.) that's formatted into fat32 (so both Linux and windows can access it's content).
3. see 2 and yes, IMHO read/write means view files and add files.
If reinstalling XP is not a problem for you I'd sugest giving it a try. Also note that when you re-install windows when Linspire (or any other Linux distro is installed) it might become unavailable (windows will probably remove the bootloader from the MBR) so always install Windows first.