To get to the point, i would be 120 to unlock all instance. You can level him more as you like since its up to you.

Well. i leveled my alchemist to lvl 100 and reborn him since i didnt feel like getting him to 180. But the way i build him is that i made him a knight mage so that he has the knight JS and is also int based instead of the usual str. He end up being my main because of the 20rc lol.

Vip cards allows you to buy expensive things, usually in stacks of 10 and buy it half price.
For example: refined gold from hawaii in stacks of 10 cost 2m total to buy. I equip vip card with me and instead get it for 1m