My first experience as a tank - I thought I was playing WoW for a second

[Lammas]

I’m actually a tad worried about this going forward if we get a new tank or healer, jobs that might start at highe levels and thus start at a more difficult starting point for that role.

Yes we can see/feel that Tanking/Healing is stupid easy but a first time Tank/Healer in that DF level? What about the next one if they start at 60?

GNB and DNC start at 60. The next expansions additions would most likely start at 70.
BTW we already have people starting their very first job at 70 on any role and trying Holminster Switch as their first dungeon without any prior experience of party content thanks to jump potions. The stories I've read don't paint the prettiest of pictures of how well it works out. I believe the game just plops you in with no tutorial whatsoever but I'm not entirely sure as I have never seen what exactly happens when you use one.