First, you're better off asking in
The Workshop- that's where these kinda questions belong.
1/ They're called
pixel fonts- try Redensek, Silkscreen, supermarket, or 04b_03b.
2/ That's a grid pattern you can make on Photoshop. Make a 3x3 (or 5x5, or any small square) transparent canvas and draw a pixel cross, define that as a pattern using the Edit menu, then go to the image where you want to use, hit Select All (Ctrl+A), then Edit >> Fill, select your pattern, and the rest should be self explanatory.
3/ Just cut stuff out and leave no background. In other words, all you really need to do is open a blank transparent canvas then do whatever you want.
4/ You can Google them up.
5/ Well, there are various ways to do this. Draw a bar, select a rectangular area then use the fill tool, or just use the rectangle shape tool.