yes
Click on Tool with left mouse button and hold down, it will show you hidden tools for that particular set of tools.
Go on http://www.photoshoplab.com/photoshop-tool-basics.html and it tells you all the tools meanings (:
photoshop
The answer you are most likely looking for is Tools, if you are referring to the icons from the Tools pallate on the left side of Photoshop.
Photoshop is more advanced and has more tools.
microscope microscope needle
It is question for Photoshop and Illustrator developers, which tool is from which app but Illustrator have Photoshop raster filters, that's for sure.
In Photoshop go to File > Automate > Photomerge, from Adobe Bridge go to Tools > Photoshop > Photomerge.
Selections tools inside Adobe Photoshop are : Lasso tools, Marquee tools, Magic Wand and Quick Selection, Color Range from Select menu and you can also trace edges with Pen Tool or Magnetic Pen Tool which is accessible when Freeform Pen Tool is active.
Yes you can, Photoshop 64 bit have exactly same options and tools as Photoshop 32 bit.
There are around 100 tools and features on Photoshop, and you will just keep finding more and more :)
All tools like Move tool, Brush tool, Type tool live in Toolbox or tool panel as you say. It is one of most important panels in Photoshop, you can not access tools in Photoshop from any other panel in Photoshop.