What about the ending didn't make sense to you?

And vistas like Gaur Plains, Eryth Sea, the swamp at night, the Bionis's chest cavity, and Saturn/Jupiter/Mars.

Good try.

I did use that often, however, when I was fighting a large number of enemies, they were still able to masacre one character while I was focusing on one of them. There were also really few attacks that could damage a lot of enemies.

It is without sarcasm that I say "you're doing it wrong."

Who do you have in your team? What skills are they using? Most importantly, are you using your armors and gems to maximize your characters' agility, or are you focusing on Defense?

lrn 2 Melia

I simply did as many side quests as I possibly could such that I become overly powerful for the later stages making it unnecessary for me to worry about team strategy too much.

I'm 150 hours in and still have the final section to explore (Junks takes you there).

I'm one of those people that has to do absolutely everything before moving on the next games. So The Last Story sits neglected on my shelf while this massive masterpiece remains selfish of my time.

But...every character has plenty of attacks which damage lots of people (check the arts log for details)...

What's your party? Are you using Melia? Riki? Dunban? If not, why not! They have plenty of attacks which affect multiple enemies; infact its their best trait!

reviving fiora was annoying... IDK the battle system was pretty good, not the best not the worst. It was the best xeno battlesystem (which isn't saying much XD) (though I still liked xenogears a lot more as a whole), Pretty damn great game imo, though I can see why you don't like it.

The scope is jawdropping (on dolphin emulator atleast)... That's what made the game for me (and playing my 2nd playthrough in my undies). I don't think I've seen a JRPG, or many games with this kind of scope.

Normally: Shulk - Dunban as the leader.

Sharla as second choice.

Everyone else mixed up for third.

Also, I wore attack, speed and muscle jewels normally.

That's a good setup (really there are very few "wrong" setups as long as someone in the trio can do some sort of healing), the key often is managing aggro, so that the person being attacked is someone who can take it, which is why Dunban and Reyn are useful. Fiora is also good at drawing aggro because of her comparatively rapid auto-attack, though her relatively low HP can also make that a liability.

I believe he.mentioned mid-game spoilers? 

Best party is Melia-Dunban-Riki anyway. Good topple rate, solid healing, strong ether attacks, good.chain attack ability, great range and multiple attack abilities etc.