1. if you dont want to text edit them then there are several ($) utilities that do it for you. im a bit behind the times on this front so im sure someone else will have suggestions.

2. to paint skin textures youll need some form of projection painting software. ie: bodypaint, mudbox, zbrush, etc. again im not sure what cheap/free software is available lately.

3. you dont need to release hair with your characters - thats a totally separate market. although for full compatibility its best that when you create your characters you do NOT morph/move their scalps.

4. morphing doesnt alter UVs at all, so the UVs - and resulting templates - will still be the same no matter how drastically you morph your figure.  extreme morphs can STRETCH textures, however, due to the base UVs not being optimal for the new morphed shape. theres not much you can do about this when creating content for 3rd party figures, except to pay attention to texture stretching while morphing. in apps like zbrush you can load the figure texture to see how the texture reacts to your morphing.

all of the above refers to custom morphs, btw. ie: morphs in an external application (or inside poser with the morphing tool), not dial twist morphs.