It's not like GIMP is an MS Paint competitor. Of course not. Paint actually has tools for drawing graphics primitives like lines, circles, and rectangles.
Linux can read NTFS, it's writing that's the problem. Linux's NTFS write support is limited by several factors, the most major of them being the fact that it can only edit existing files and only without resizing them.
As for booting, GRUB supports standard chain loading so it can start another OS's bootloader (eg ntldr or the bootloaders used by the BSDs), but for reasons unknown, the Windows installer wipes the master boot record and then does nothing to it, so if you want to dual-boot and you upgrade Windows (or install it second), make sure you have a Linux recovery disk handy to restore GRUB.
Linux can read NTFS, it's writing that's the problem. Linux's NTFS write support is limited by several factors, the most major of them being the fact that it can only edit existing files and only without resizing them. As for booting, GRUB supports standard chain loading so it can start another OS's bootloader (eg ntldr or the bootloaders used by the BSDs), but for reasons unknown, the Windows installer wipes the master boot record and then does nothing to it, so if you want to dual-boot and you upgrade Windows (or install it second), make sure you have a Linux recovery disk handy to restore GRUB.