Skillpower adds to the base HP of the shield. It's not worth dumping points on Electronics to boost the shield, but if you have a Specialized backpack (what it looks like you might have) that adds about 20k skillpower for a very low investment which should give you all the shield toughness you need so you can use your performance mods on +ballistic shield damage.
edit: Barrett chestpiece is super good for that build as well, looks like you have a good setup. Not sure how well it translates to PVP but I heard a shield can be useful in a group.
DZ drops all the same gear, just more of it. I went back for the first time in forever last weekend with some friends because someone needed to farm up DZ funds this week. Turns out there so much loot and and you only have 9 slots to carry gear to extract, you end up picking and choosing what to extract. It was so much gear that we could call in an extract, kill the NPCs that arrive, put the first bag on the chopper, and run around collecting loot and get a 2nd bag on before it left.
Also, since there's so much gear, you end up caring less about losing it in PVP, which leads me to believe that it's turning into more of a dedicated PVP zone. Some guy picked a fight with us 3 times. I don't know why, but he certainly didn't have much to lose.