Smallish group of questions.

I am using Blender 2.7.2.

I know that I can use <ctrl> + <LMB> to add points. In <tab> mode, I can selet the ones I want,
and press <f> to create a surface, by filling. I can even go <p> to have a separate object.

-If I have additional, bisecting points on say a path line, there is a keyboard shortcut to
normalise away additional coincident or touching points away that I don’t want. What
is the key combo to do this? Without selecting in the w menu, what keyboard keys do I use?
(Is it remove doubles?)

I am using bezier curves or nurbs curves (two separate cases).

-If I have the curves touching, in a circular bezier arrangement of say, three beziers as one loop, how may I fill and generate a NURBS SURFACE surface automatically between?

-Or even if I have two separate nurbs curves which have two straight line distances between their end points?

*(I want to acheive construction and filling (NURBS SURAFACE GENERATION )with these points, and not by editing
multiple a NURBS surfaces and putting them together).

-Is it possible to add Textures to a surface before rendering (or backing) inside Blender?
How do I find and activate the menu which inserts a texture from an image file?

Before rendering using what? Cycles or Blender renderer?
Reflections are determined by Material Mirror properties for BI or use of Glossy material node in Cycles.
Texture also belongs to some Material: choose one and add Image Texture either as a new slot or Node (BI and Cycles). Set Mapping and influence appropriately to your needs.

Circular Bezier arrangement fills automatically if that is set to 2D.

Two separate - convert to the Mesh - Alt-C and fill using Bridge or any other way.

Pass on NURBS. That’s in works now. What’s there already is almost never used unfortunately due to different reasons.

What is meant by “say a path line”? Are verts connected by edges?
For “shortcut to normalise away additional coincident or touching points” in general - w key, Remove Doubles and adjust on the Tool panel bottom part Merge Distance as needed.

Circular Bezier arrangement fills automatically if that is set to 2D.

-How do I enable this? Is there a key shortcut, and if so, what is it?

-Can I do the same, using NURBS curves, to construct my arrangement
and fill in a rounded NURBS curve surface, and not just a 3D mesh?

-What is the one key shortcut for Dissolve Vertices? I already know it sits under the <x> menu.

-Can you apply textures before rendering, or not? If not, where do you apply textures
from file images anyway?Where is the menu to insert and align textures to a face or a
surface from a file? Is there a key shortcut, parallel to <f> with meshes?

-This works already, and I have been familiar with it. This technique will generate a flat plane, across
my Cyclic Mode enclosed Bezier Curve(s).

-I want a 3D fill that generates a curved surface, and not just a flat one. How do I do this?

No, you can not “skin” set of bezier curves while these are curves but you could get the corresponding surface mesh by using such set of curves and Bsurfaces addon. It is partly broken for the 2.7(1,2) unfortunately. You would need to get older Blender build to use it.
Here’s the video of what addon does - http://vimeo.com/26339130