So, yeah...as you said, missiles that look like tablet pens...this kinda reminds me of the mechs from Lost Planet, even though they're very different. Like, the mechs in LP, (Vital Suits, were they?) you put guns on that you could detach and use on your own. It kinda looks like this robot uses guns that it stores on its legs. And I don't think the VS pilot was as exposed, but aanything to see a hot chick piloting a robot, right?
Well the chest opens to reveal the pilot. The transparent green parts all fold in to protect her. I didn't specifically try to reference any particular mechs but I probably took the most influence from Full Metal Panic.
Well it's tough to say since there isn't much in there. I could tell that armor you drew looked like the drewmer armor in Skyrim. I would say find out what you really want to draw and focus on that. Immitating a style (like Skyrim) that you like is a good place to start.