Path of Exile

I'm a D3 player looking for something to tide me over until RoS comes out and (hopefully) fixes D3's problems, and I have a few questions:

1. It is my understanding that the character customization is one of the main reasons why PoE is "what D3 should have been", but what other advantages does it have over D3? Does it have the actual Endgame content that D3 lacks?

2. The character customization, exactly how much do we get to experiment with it? Do we get to fix mistakes, or is it like pre-respec D2 where we have to start all over again to fix mistakes/swap things up because we found a legendary that would make another skill better than what we've been using?

3. Furthermore, since you can apparently use the Skill Tree to boost anything and from the sounds of things make Marauders with magic abilities, I'm wondering, are such hybrid builds viable?

4. How is the EXP curve?

5. Since there's an EXP penalty upon death in this game, I'm wondering, does the game have cheap deaths like D3 has when you fight, for example, Vortex Arcane Enchanted Fire Chains enemies in narrow spaces or anything of the sort?

1. Endgame content in Path of Exile is often referred to as "Maps". It works like this;

• High level enemies drop maps at a semi-rare rate
  
• Maps are placed into a machine that you gain access to shortly before the end of Merciless (the highest difficulty).
  
• The map is consumed to randomly generate a high level area based on the name of the map you put into the machine (Dungeon, Dried Lake, Dunes, etc)
  
• Maps can be Magic, Rare, Unique, etc. just like regular items. The modifiers will increase the difficulty of the area but also increase the quantity of items that drop - for example, "Area has patches of burning ground" or "Player life regeneration is halved".
  

2. You get "respec points" from quests that allow you to refund a spent point. You can use them to fix minor mistakes. You can also use an expensive currency item to give you respec points, but it's inadvisable to do so for large overhauls unless you're like, level 85+.

There are plenty of skill builders/planners both offline and online that make the whole thing a lot easier.

3. You can make any class into literally anything you want - A bow-wielding Marauder, for example, is a strong and completely viable build.

4. Exp curve is great until around 85/90+ from what I've heard. After that it realllly slows down.

5. Modifiers on yellow enemies are not anywhere near as devastating as they are in D3. The most dangerous thing is probably Reflects Physical Damage/Reflects Elemental Damage and even then it's not going to kill you unless you went complete glass cannon.