1. There are a bunch of python scripts that come with blender.  Create a new window in blender (left mouse click on a window edge to split it), change it to the scripts panel (click the left icon in the new window button bar and change it to scripts, the snake one).  Then click on the scripts menu, go to mesh, and I think poly reducer does what you want.  Or possibly Mesh Cleaner.  There are lots of good things in there, I suggest experimenting with them.

2. Just to the right of the box that says Object Mode or Edit Mode or whatever there's another box with a cube in it.  That's the draw type box, change it to textured to see the textures.  It may or may not work with your UV mapped textures, depending on how you've done them.  I blame the game engine. (bah, grr.)  (I'll explain that as part of 3.)

3. Everything in blender is pretty modular.  There are textures, which are part of materials.  Materials can be applied to meshes (or nurbs surfaces, or lights....), and meshes (or nurbs, or lights) are part of objects.  Objects contain information about scale, rotation, and position.  Meshes contain the positions of each of the vertices, which are connected, and which form faces.  Materials contain color, specularity, reflection, transparency, abience, etc., plus a list of textures that may modify those values.  Textures contain fractals or images (or video, and possibly some other things).  I actually started making a tutorial on this stuff, but never managed to finish it....

If all you want is a solid color, don't bother with the texture tab.  Just change the top color value on the material tab.  This color will show up in textured draw mode.  If you want a fractal color texture, there are a couple things you can do, but both start with going to the texture tab and getting a fractal you like.  For the sake of demonstration, use stucci.  This fractal can modify any value that's set in the material.  It will change them the most where it is white, and least where it is black.  Now go back to the material panel, if you've still got the default gray material the texture preview should be pink.  Change that one from the texture tab to "Map To."  New textures are automatically set to color, so that button should be depressed.  Click that and the pink should go away in the preview.  See the big pink box?  Change that color to something else.  That box and the other color box are the simple way to add color fractal textures.  You can add multiple textures to increase complexity.

The more complicated way is back on the texture panel.  Change the first box from Texture to Color and click the Colorband box.  There's a slider on either side, and you can add more or remove some.  The one on the left has a default alpha of zero, so that means the color never shows up on the material there for this texture.  You can change the color and alpha of each one.

All textures are mapped to the original object space, but for complex ones you'll probably want to UV map.  Most tutorials about UV mapping talk about image textures, but it's often valuable to use them for fractal textures, too.  I won't tell you how to UV map here, but you can switch from object space to UV space on the Map Input box (another tab in the Texture and Map To box on the Material panel mentioned above) by changing "orco" to "uv."

You can also add image textures instead of clicking on one of the fractal names when you add a texture.  The way you add image textures for the game engine and for the render engine is different, and the texture draw mode uses the game engine method.  If you add it via the dialogs in the texture panel, it will show up in the render engine but in the preview may show up pink, black, or white.  If you want them to show up realtime, you'll have to also go to UV face select mode on the object, select everything, open the UV editor window, and load your image there, too.