basic modelling takes care of 75% of your texturing, it crosses over so much nowadays, that basically there isn't much of a separation between the 2 as far as job descriptions go.
I will grant up this- it is harder to make good textures. and time consuming. but it is just more involved 3d modelling for the most part. then just scratching it up and throwing grunge brushes at it in photoshop.
Collision and normal maps are simple though XD The normals can be made using the texture, and collision is just a few clicks.
that depends.
once you have your high poly, which can be a big chunk of the work depending, you bake out your basic normal map, and an AO. from there you can also bake some materials.
then you get onto what people generally consider texturing. by that time you are usually looking at a good start, and you can pretty much do anything and it'll still look alright.
even architectural models, like bulk head walls or whatever are made in a similar fashion these days, ie baked normal maps. Even landscape textures have baked normal maps. ie look at the rubblebrick.dds. in all the texture replacers, No one has actually be able to make a better version than vanilla, because they are going about it all wrong. that one needs a 3d modeller to bacially throw a bunch of 3d bricks around and bake them onto a flat plane...
this is a version of the groundlitter textures that I made using partially baked normal maps.
http://www.fallout3nexus.com/imageshare/images/209926-1268408617.jpg
http://www.fallout3nexus.com/imageshare/images/209926-1268408721.jpg
i'll up them somewhere if anyone wants them to use or for research purposes.