1. A motion scanner can't be added to HWPs. One, it's disabled, two, the AI won't equip it in the hand slot, making it unusable.
2. You can add another motion scanner, but the only meaningful thing you can edit is the TU cost and whether it is % or flat cost.
3. Such an "armor", however, is perfectly plausible... but the immersion could shatter with a dog-soldier wielding a Rocket Launcher and hauling 3 rockets, 4 grenades, a pistol and a medi-kit in his inventory
![Smiley :)](https://openxcom.org/forum/Smileys/default/smiley.gif)
4. Yes the sprite is converted from Wolf 3d.