Wait, there's level scaling? I actually had no idea about that. I have been trying to keep my entire party around the same level, but certain characters (like Anna, mostly) tend to just shoot up in level due to her ability, so she's level 12 while most of my party is 10, for example (a few elevens in there).
I'm having to remember my FFT experience from way back when I played that for the whole 'losing characters' thing, yeah. Although in that game you could revive people which is another element entirely.
Probably the biggest thing to remember that I'm still getting used to is that you really have move in groups and focus fire to take enemies down, you can't just send in your ringer unit and have them mow down multiple people by themselves. I've also noticed that the enemy AI (at least so far) seems to be pretty good? They're good at positioning to avoid getting backstabbed, avoid being able to be follow-upped, etc.