at the moment I am wondering if I have proper Enchants / gems put on my gear. The reason is my relatively low HP I think.
Raid progress is currently Naxx 10 so I would appreciate it if you could give me some advice regarding my enchants and gems - have I done it wrong or is the Health pool okay to get Naxx 10 clear? (I am currently working on the damn Herald Bracers from Ahn'kahet)
This may just be a suggestion based on taste, but you could replace your +22 agility enchant to cloak with Titanweave (+16 Def rating) and enchant your chest with Super Health (+275 HP, Enchant Chest - Super Health - Spell - World of Warcraft). It'll still leave you with above 540 defense.
That's what I did recently since I've been kind of paranoid about having low health. Also, you can look out for Minion Bracers (Minion Bracers - Item - World of Warcraft) from a random trash drop in Naxx and put +40 Stam on those.
Otherwise though, you're definitely good to clear Naxx 10.
Your fine to MT 10 man Naxx, the biggest reason your HP is low is cause you don't have a defense trinket, I'd recommend farming Regular HoL for Seal of the Pantheon - Item - World of Warcraft. That way you can free up some of your gems so you can stick in some Guardian Twilight opals which will get you closer to the expertise soft cap and give you some more health also.
Your HP is definitely more than fine for all of Naxx10 - in fact, all your stats are, from what I can tell. A few suggestions, however:
You'd do well to change your bracer enchant to either +40 stam, or defence (my suggestion would be stam), and your cloak to Titanweave to get some more defence. After that, change your meta from the stam/armour one to the defence/+10% SBV one. This'll free up a few of the sockets that you have going for defence, which you can change over to stamina gems (or stamina/X, depending on socket colour).
Gear wise, I'd work on either getting the Seal of the Pantheon, or the Essence of Gossamer, which has a huge pile of stam on it (that alone will get you an extra 1176 HP before kings - with kings it'll give you 1364 HP). Of the two, I would personally go with the Essence, as it's really one of the best trinkets currently in the game. I'd switch that in for your Valor Medal of the First War for just about every fight save Patchwerk, where you'd want more avoidance.