Some information on rewards: There's a 50 point "balanced party bonus" which seems to be from having at least one DoW, DoM, DoL, and DoH. Each time you do a debuff using DoL, you get 10 points, doing each debuff at least once gives 150. Same thing goes for the buffs from DoH. Quite obviously, you get plenty of points from keeping the front line intact: Every NPC alive, every line unbreached, every supply crate still there, plus a bonus for not losing anyone at all. You get 3000 for "Provisioner Present", which seems to be from having someone who's in the top 20 in your party. You also get 1500 for killing the stray fauna (a lemur running around) and another 1500 for defeating the beast of burden (Wolf in the last wave).

As far as strategy goes, I've found it helps to have the DoH focus on buffing the defense of your NPCs, DoL focus on lowering monster attack and HP, and have your healer take the time to buff and cure the NPCs. Your regen DOES stack with theirs (They don't receive it as an individual status), plus your protect stacks with their defense buff. NPCs are quite capable of tanking when buffed, but it can be a good idea to have some capable WARs to try and take the mobs down quick, and if you're lucky tank a few.