Yes. HTML, PHP, CSS, Javascript, etc... are all platform-agnostic. You could even host the website on a Linux server, and you would still be able to use it in Windows. Many sites do just that.
Yes, the Saitek X52 will work under Windows Vista.
Yes, CA-dBFast works under Linux Wine program, Although, it would be better under a Virtual Machine running Windows.
You can try to run it in the compatibility mode. But 99% of games for Windows 98 will not work under Vista.
Go no less than 1gb for vista.
Yes. The software needs to be able to use the commands and files that are available in Windows XP. Windows Vista will have these available as well as other files and commands that have been developed since Windows XP was released. However, do not confuse this with device drivers. If you have a piece of hardware that specifies that the drivers are for Windows XP, these will not necessarily work under Windows Vista and you will need to download the correct drivers from the manufacturer's website.
Windows XP, Vista and 7 Mac OS X It also can run under Wine(windows API translator) on systems like Linux, BSD, Solaris, etc. Also, Wine-based system ReactOS can probably run it. It is speculated that Valve will release a Linux version of it's games in the future.
Windows Experience Index
Linux has broad support for numerous sound cards and web cams. Relatively few are unsupported. In addition, some devices that were not originally intended to be used with either system, such as the PlayStation Eye, were supported on Linux first. When compared to any single version of Windows, Linux as a whole has far better device support, because Windows often drops support for legacy technologies, and if a manufacturer stops supporting a device, there won't be any drivers for newer versions of Windows. In contrast, the Linux kernel seldom discontinues support for any device and thus they can be used for as long as there is a way to interface them with your computer. If you have a PCI sound card from 1998, say a Creative Live! SoundBlaster 5.1, you can use the device just fine in Linux, but not in Windows Vista or Windows 7.
From the web site: http://www.gimp.org/windows/ Requirements (in part) GIMP should run on any NT-based version of Windows (NT4, 2000, XP or Vista). (Oct 2008)
It is just called Computer in Vista and it is located on the right side of the Start Menu under Recent Items.
Halo 2 works under Windows 7.
There is plenty of software which allows Linux to work with NTFS file system. For windows there is not as much. But I think Acronis "Backup and Recovery" allows you to read Linux file systems under windows.