I don't think I ever even had a spear user

I think if you have a guide or wiki and learned all the tricks and what skills are useful, it'd go a long way towards making the job system less offensive (although you'll still have to run in circles and grind metal slimes). That's the only downpoint of playing imports day 1. You're all on your own! Especially when the import thread becomes totally dead after a week on gaf and you're the only one still playing.
My party was a standard Knight (job changed lead into it), Monk, White Mage, Black Mage party. That reminds me how much I hated the quests at Dharma for each job. "Go kill 50 enemies with a counter attack and come back and talk to me" :'(
How much slower is the combat versus the 2D DQ games?
Couldn't I just use the same classes from start to finish to enjoy the game without grinding?
Did you play VIII? It's a looot slower than the 2d DQ battles, but it's slightly faster than DQVIII battles.
And yes, you can make your team at the start and go through the entire game and beat it without grinding in about 30 hours.