That's all good and correct info, but I'd like to add a few bonus details.

1) There is a misconception that 2.0 will be a completely different game. However, while it will bring dramatic improvements to the game experience through the redesigned infrastructure and some new content, the bulk of the gameplay and content changes will continue to be added between now and then. When 2.0 launches we will have the same classes with the same abilities and many of the same items, though we might get a slight cap increase between now and then.

2) In addition to the debuff, you do lose about 10% durability on all your equipment. You don't lose the equipment durability if another player casts Raise to revive you. I'd also add that multi-classing is required to some extent. Virtually every class has 3 or 4 abilities from other classes that make a big impact on their effectiveness. Most of them can be obtained fairly early on, below level 20.

3) There is no AH, but there is a system for buying and selling items. On most servers it's the Market Wards in Ul'dah. Players can buy items directly from the search counter, making it like an AH, but players have to set up NPCs to sell their goods manually from inside the wards. They are always working to streamline this process, but, as you can probably gather from the odd side-effects of direct purchasing, the 1.0 data system wasn't initially designed to support this.

4) Yes. 2.0 is going to have a moddable UI. You can also move items around if you click the lock in the micro menu in the lower-right corner.

Welcome to FFXIV!