Ok so I been playing around for a few days with different classes and honestly I am having a really hard time deciding on what to pick. A little background I am experienced in mmorpgs but not this one. So basically I'm trying to pick my main class.This is pretty much what I am using for search criteria on what to pick so any help would be appreciated!

1. What class would be the best at teaching me mechanics?
2. Would it be ok to just jump into tanking for first character? (I try not to do this for the first character)
3. What class overall guides you the best to the more complicated rotations
4. I am honestly torn between SMN,BLM,DRG,and BRD they seem to interest me the most but if you have another suggestion I will gladly hear it out
5. In the end I like to be useful to the group and but still be able to push some good numbers (no I don't care about topping the charts but I don't want to be struggling too much just to be viable for the first time anyway)