This is how http://www.metacafe.com/watch/400249/photoshop_x_ray_trick_see_through_clothes/
Muslin is more tightly woven than cheese cloth. One can hold up a piece of cheese cloth and easily see through it, while one cannot see through muslin.
just move the cloth out of the way
Yes, you can create animated GIF in Photoshop Elements. See related link for tutorial.
Free Photoshop site is Photoshop online. You must create Adobe ID in order to use it. See related links.
You can rank your images in Photoshop Bridge, which is program for searching images on computer, adding tags, ranking and so on. Photoshop Bridge comes with Photoshop, so if you have Photoshop installed you have and Bridge. See related link.
See related link and watch detailed instruction how to create reflection in Photoshop.
It is view mapper, when you enlarge image in Photoshop, at navigator you can see what part of image you are looking at on your screen.
Photoshop Lightroom does not have such a tool. Anyway you can use external editing software like Photoshop or Photoshop Elements. See related links for more details.
Photoshop does not have liquid layout, probably you hear that term for Adobe InDesign. See related links.
Extended is the top product, it takes everything in standard Photoshop and adds 3D and video capabilities, and more... (see Related Links below)
Layers are pictures stacked one to another, Layers can contain transparent pixels so you can see through Layer above what is on Layer below.