Chocobos...it makes perfect sense if you think about it! Boco if you're looking for a specific character
1-All things considered, I probably shouldn't exist. - FF1 was the "Final" game, or so they thought. Chocobos appeared after that.
2-For such a fantastic critter, I've sure got a mundane job. - Chocobos can do lots of things - fly, heal MP, even fight, race, etc. However, they're generally considered mascots, which is fairly mundane.
3-Well, I suppose it's not technically a job. It's not like I get paid. No matter how long I've been doing this. - Mascoting isn't a real job, and they've been doing it for a long time with the series.
Not necessary, but damned if it doesn't make sense.