Normal parties in FFXI just don't happen unless you get 5 others to agree and join you. And even then most will add FoV for extra EXP.
As for talking, type something up and see if you get a reply. There is not a lot of strategies needed to be talked about on party mobs in a game that is this old. If you do not know how to kill a crab a X level, something is horribly wrong.
As for ninja. Yes and No. If you buy the ninja spells off the AH/players plan on paying a lot. If you raise fame and do the quests then you will save yourself money. Each spell still takes a tool, but one of the neat things I found out when I had returned was that NIN as a main could buy 3 tools that could be used for multiple spells. This saved inventory space.