If you need healing, try using the manly party (Shulk, Reyn and Dunban), linking Shulk's chain attack heal skill on everybody. Also try giving Reyn his more offensive skills (use Magnum Charge only if you're manning him though). He doesn't output as many criticals as Dunban, but he can be a beast on chain attacks.
-Finding NPCs again to turn in quests basically requires a quick run to the online wiki to find out where the heck they are and what times they are active
-The animations during combat can sometimes lag a lot causing instant death because you couldn't get a crucial shield off
-Armors look really bad
A good trick to find NPCs is that their active time window indicated in the affinity chart is the time they're in the gameworld, not the time they're in their default location. So what I did to find some NPCs whose default location I forgot was changing the time to the beggining of their window, which is the exact moment they spawn. But they won't spawn in their default location - they all spawn at some building's door, and tracking those is easier. For timed-quest-town, they all spawn from some teleporty-looking things, so I just tried one after another.
-I always considered the animation lag an essential part of each art that helped define it. For instance: Shulk's Daze art, whose name I forgot but that has the same animation as Turn Strike, has a relatively long wind-up animation, which maks it harder to land it before Topple wears off if you weren't paying attention. But Reyn's Wild Down, his Topple art, has a, while only moderately long, very recognizable wind-up animation, so if you see recognize it you can start not-Turn Strike before Wild Down lands, and it'll inflict Daze very in time.
So yes, I learnt how to take advantage of wind-up animations. Hell, the second superboss is a mechon, and when you get closer than a certain (loooong) distance from him, he'll start the fight using an ether-based line-AoE art. Playing as Shulk, it'll always trigger a vision (unless you've linked a certain skill from Melia that greatly reduces enemy AoE ether arts' damage). Shulk can also have a skill that completely fills the Talent Gauge whenever a vision appears. And shattering a vision boosts the whole party's morale. Shulk can also have an optional Monado Art, Armor, by that point that reduces all physical and ether damage received by the party.
Thing is, if you use Armor after the vision starts, you'll shatter the vision, but you won't have the talent gauge to use Enchant right away, and the enemy has Spike. But if you use Armor before the vision, then the damage you'd take from the attack won't be high enough to trigger a vision.
Solution? You start Armor before the vision, but time it so that, before its wind-up animation finishes, another party member has gotten close enough to aggro the enemy. That is - the vision starts during Armor's wind-up. SInce the Talent Gauge emptied when you started Armor, it'll be filled again by the vision (so you'll be able to use Enchant immedieately afterwards), and when Armor's wind-up animation finishes, it'll take effect and shatter the vision, boosting the party morale. You get more time before the enemy attacks (vision countdown), you reduce its damage, you get to use Enchant (or whatever else) immedieately, and you get a morale boost. Win-win-win-win.
And armors look hilarious. If you haven't already, you should definitely have a fashion session where you link a Heavy Armor skill to everybody and check how each different model of heavy armour looks on them.