Thank you for your replies. It does seem as though I will have to grit my teeth and try at least a few dungeons using PuGs.
I have played WoW and mostly solo that as well, but I have had to run a few dungeons with PuGs for a particular storyline (Alliance BfA progression and SL Kyrian covenant), but I made sure never to run as a tank or healer as they always really need to KNOW exactly what they are doing or the quest fails.

Final question (probably). I get to L80, full of the joys of spring and all that, do I lose access to all the things I've unlocked on the way to L80 when you start another job at L1. For example, would I have to requalify through the MSQ for the NPC retainers that help in dungeons or are they available when I reach the appropriate level, or requalify for the chocobo when I reach L20 if I've already unlocked it once?