1. Yes. You need to download the new client that has the europe update in it. They will not be offering an autoudpate feature with this update because of the size and the strain it would put on their servers.
2. Yes. If you wish to continue playing silkroad after they release this update (July 24th) then you must download the new client. The game will not run with the client you currently have,
3. This is in reference to weapon\gear degrees. There are 3 tiers per degree. I will take 8th degree for example.
Item----------Tier 1----------Tier2----------Tier3
Weapon-------64--------------68--------------72
Hands---------64--------------68--------------72
Shoulders-----65--------------69--------------73
Feet-----------66---------------70--------------74
Hat-------------67--------------71--------------75
Pants-----------68--------------72--------------76
Chest-----------69-------------73--------------77
Rings-----------64--------------68--------------72
Earrings--------66--------------70--------------74
Necklace-------68--------------72--------------76
Knowing the tiers will help alot because as you see above, lvl72 can be a VERY expensive level to get to. You have to get a new weapon, new hands, pants, 2 rings, and necklace.

So knowing this well ahead of time will help you save and not be too poor when you get there.
Moved to Questions and answers.