First off, I'd get another 33 dex somewhere. It's the cheapest way to increase your survivability right now.
Your resists could be a little higher but looking at your gear, it's not going to be completely cheap to upgrade some of your pieces. Because your armor is so high, you'd actually gain EHP by converting armor to resists at this point so I'd probably target switching your boots with some that have higher resist. Your pants and chest are OK.
1. After boots I'd look at getting a better amulet. Consider getting one with LoH since it's one of the few slots you can get that on. If you want to go crit down the line, check out crit amulets but they're probably crazy expensive. One of your rings is OK but not the best (the one with just 100/100 str/vit. I'd try to get crit, ASI, or more resist here. I don't know EU market but if you just pick one of those stats + str or vit you should be able to snag one for a decent price.
2. Your DPS is definitely low. I'd search AH and see if you can pick up a 800 DPS weapon w/ socket and STR or VIT and put in amethyst for LoH. I think that's the cheapest way to go about it. You have a lot of strength for only 8k dps which is going to be a huge problem in A2.
3. I actually don't think it's a good deal for you to upgrade gems at this point, especially if you only have 4mil gold to work with. +4 stats isn't going to be a big deal and that money can be spent to upgrade other pieces.
4. Not sure on prices. You could definitely do the zrave strat on your chest, dump it for a lot of gold then get a piece with high STR/VIT/life% and sockets. Basically use the
EHP calculator to find one with similar EHP and come out ahead. Your bracers wouldn't be worth much on US. 60/60/80 stuff sells for about 400-500k here I think. Not sure about EU.
The main thing with A2 is a lot of the enemies are annoying as hell so you want to kill them faster. I actually run A2 with about the same EHP as you but but I have 400% more damage. I couldn't imagine being able to survive some of the stuff out there taking 5x as long to kill stuff.