This game is modeled after WoW so you are probably not going to be happy with the way things are going to go. My advice would be to check out games like GW2 and EQ2. If you play the right classes and have real skill for it you can basically do everything in those games solo or with one other person. EQ2 has a massive world to explore because its been out so long. Play a SK or an INQ and pick the appropriate merc. Then you can pretty much do everything up to the very very end game content solo. GW2 is a bit more difficult but with a warrior and a little patience you can solo most of the dungeons. There are a few that have mechanics which prevent that. Maybe more now since they made some changes to the dungeons. But still a lot of them should be doable.

FF14 is too well balanced class wise for that sort of thing to be effective however.