Some other random stuff:
1) Hold down left shift to highlight items/interactable objects. You will miss a ton of shit if you don't do this.
2) People outlined in blue can be interacted with (are plot-related, will give a quest, are merchants, etc.).
3) Apparently stealing is broken and overpowered; you can steal the most powerful items from merchants with relatively little risk (just save before you do). I haven't done this, however, so I can't vouch for it.
4) There is a merchant named Malachi who will be present if you have the Deluxe version of the game. He sells some pretty powerful magic items, but they are not cheap. You will not meet him until the refugee camp.
5) For two-handed characters there are actually two feat trees you want to pay attention to -- the two handed tree, and then actual weapon type tree (sword, axe, hammer). In my opinion, it makes more sense to go down the two-handed tree first and get Precise Strike (good damage booster) and Second Wind (a minor self-heal that will be useful in tougher fights). Then start going down the weapon tree you want to specialize in.
6) Feats and spells that cause Stun are quite useful early on. Summons are also useful for adding a seventh party member in a pinch.
7) There are at least two opportunities to get mercenaries in your party, early on. Spend the money and take them. Having a filled out party roster makes a huge difference in your party's survivability.
8) When it comes to locked chests, you will have two options to open them -- picking the lock, or forcing it. Your ability to force locks is determined by your Athletics skill, which is also used for things like climbing rocks and jumping over pits/gaps/etc. I'd highly recommend taking athletics, since so far it seems to be used quite a bit. You will meet a thief very early on who can pick locks, but I was not impressed with her success rate and I just went around forcing chests open.
9) Setting up backstabs is difficult, but worth it when you can pull it off. The best way to do it, I've found, is to have your thief move waaaay out to the flank(s) and only start moving back in after enemies have solidly engaged with your other characters. I've seen backstabs do 50+ damage, when my two-handed warrior is doing a respectable 20. They won't work all the time and in all situations, especially in tight quarters. But they are worth using if you can get them set up.