First I think you missed what the 2nd M in MMO means. Multiplayer. It's something that you gotta consider when starting this kind of games. Play and interact with others. If you want to play solo and just watch random people moving left and right to fill the environment, then you are playing the wrong genre IMHO. And this probably answers most of your "I can't play the whole game solo" points.

About quest items, yes they give you equip, but it's for your first job.
Once you start levelling other jobs and the quests are no more, none will give you anything anymore. You don't wanna level other jobs? Well, it's a game mechaninc and the game is built around this. If you don't like this kind of system you should have gathered more info beforehand.

My .02

[Following "hush whiteknight" post]
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