Returning Player
Welcome back.
I would start by reading this: http://www.reddit.com/r/Guildwars2/wiki/returningplayers
After that we can answer more specific doubts.
(and the other 8 elite specs maxed too)
I’d say you will see many come back or new players (e.g. saw many ~1000 AP players in dungeons, many are first timers), which is very important imo for the game stay vibrant (not just a bunch of old players). The game world and interests are huge (PvE, metaboss event, sPvP, WvW, EotM, crafting), it would be hard to find time to do everything. Just see if for yourself. P.S. Birthday gift is just some boosts and a gun that shoot cakes.
To answer the birthday gift question, every character gets a birthday gift once it turns a year and then two years old. Year one contains a mini Queen Jennah, a birthday booster (gives you a 100% boost to magic find, experience, wvw experience, gold from kills, and 10% bonus to spvp reward track progress), and an experience scroll that let you go to level 20 on a low level character.
Year two gives you a birthday blaster, birthday booster, a skill point scroll, and another level 20 scroll.