1. Do we know how many raids will there be on launch?
2. Can someone share their experience with playing as a healer? Isn't leveling too hard when you're spec is healing?
3. Do you get the option to switch between two specializations at some point?
1. 2 raids, a 20 man and a 40 man along with lots of other late game content including heroic dungeons, adventures, world story instances.
2. I wrote up a moderately in-depth impression of healing a page or two back. You won't have any issues leveling as a support. You'll still do enough damage to kill stuff alone, which leads into..
3. Yes, i think around level 10 or so you get a second action set which is a completely separate set of AMPs and abilities. You can swap from healer to dps on the fly for easier questing.
Quick version of healer breakdown:
Medic: fast paced with lots of utility, close range healer with lots of aoe and short range heals.
Spellslinger: longest range, has to aim their heals. relies on their innate (spellsurge) for burst healing. hard to play.
Esper: more 'normal' healer, mix of targeted and aimed heals. More medium range compared to spellslinger.