2.5s gcd isnt that bad at 50 , u have some skill speed and some skills OGCD

quest with items , right click on the item window that pops and will auto select the item for u , no need to open inventory or anything

dungeons limit is to avoid ppl staying in dungeons for hours (u didnt played in 2.0 , dungeons had queues , u were stuck 30 min "reserving instance" because the instance server was full)

low lvl anything is boring , because u use 2-3 skills :P it gets better at 30+

welcome to Eorzea btw ^^/