Job Specific Traits?

[RitsukoSonoda]

*snip*

That again had nothing to do with job specific traits. It had to do with either the job kit or the type of damage the job excelled at. 5x DRG + BRD merit party on colibri was popular because DRG dealt high amounts of piercing damage which most bird enemies like Colibri had horrible resistance against. RNG also did huge amounts of damage to birds with bows however DRG was favored because they could sub WHM and self sustain easily thanks to their pet. Also a majority of your examples apply to only exp/merit parties. In actual endgame nothing was completely excluded or unviable. However like FFXIV some jobs saw infrequent use either because something else just did it better or in the case of BST it was viewed as a primarily solo content job by the community and only used in rare instances where disposable pets made things easier.

As for the wait on EXP parties. That was pretty much the DF of FFXI and the DPS queue sucked as bad or worse than it did in FFXI even when people finally figured out DPS cannon parties work. However if you were a RDM or BRD you had to go /anon if you wanted to do something on that job otherwise you were spammed non stop by /tells asking if you'll join their exp/merit party.