I think it's looking good, I would revisit the abdomens though. They're too uniform and also, as far as how many there are, usually the top two are right under the pecs. And you currently have a 10-pack abs and the usual human has 6, at most 8. Keep up the good work!
The fact I don't usually use xNormal is my problem :p In fact, I tend to stay away from high end baking and programs, and usually make as much as I can by hand. When I use xNormal, my maps either come out garbled, or pitch black, for example:
Unfortunately Photoshop is a photographers oriented software - and they have rather straightforward workflow - they rarely need to perform such a complex tasks as texture artists usually do. I have doubts that Adobe gonna one day change this run of things - photoshop is an industry standard and real changes in this case…
I don't know about integrated graphics but usually theres a toggle to turn it off in the bios options, when your booting up press whichever button it prompts you usually delete or f8 and take a look around for bios for anything that says graphics or gpu or integrated graphics or somesuch and turn that off.
for leaves strangely enough the overcast day thing is the opposite of what I want usually haha. I usually will try to find the leaf/branch I want and then hold it up against the clear blue sky. Try to be completely in shade though so that you don't get weird highlights on your subject.
I'm with Renaud. I usually want people to stick to the original material more closely, but that's usually because when they don't, it gets all fucked up. I think you're doing a fine job of capturing the "Tank Girl" look, while giving it your own spin. She looks great btw!
It's closer to the pose the character will normally be in, our rigs usually aren't sophisticated enough to deal with extreme deviation from the bind pose so this leads to less artefacting, less of the time It's the same reason that a T-pose isn't usually the best pose to model in for game characters and we mostly go with…
Spec maps have no effect on metals. Usually a single number value is plugged in into the specular node if you want to change something (although most times it's just left alone). The opposite of metal in UE4 is the 0 value. So you use that, and continue your roughness/normal/AO workflow as usual.
I know guys that rotoscope photographs onto their sculpts. You'll see this happen a LOT, particularly on Zbrushcentral. I can usually pick it out, but a lot of those guys DO have lead jobs at prominent studios. It's usually why I prefer seeing hand-painted folios, and texture flats.
If you want full hands (don't forget that the hand itself can also bend as the metacarpals move, though usually 1 bone in the hands is ok) it looks as though you are going to be riding that limit. Is this a limit for an engine you are working with or just a random guideline? These things are very engine specific, usually.