subclassing.
I might have given the R sniper. I might be the only one who advocates this, but I felt like without a sniper I kept getting awesome bows without anyone to give them to. Having a subclass sniper lets dude use bows to conserve TP without dps going to zero, and having some accuracy boost is super useful every now-and-again when you run into evasive enemies. Plus, having Leg Bind has an option is good when you encounter shinnies. However you invest, sniper is a solid off-class for someone you're not otherwise committed on.
Dancer seems to be consensus for F, I use it myself.
For Landsnotrug R seems as good as any, if just for elem boost. I'd keep skills in L tree mostly though.
I've got Arcanist/Medic as my primary healer and his passives in/out of battle are surprisingly viable on normal but you NEED a level 5+ heal and a revive in your party. I'm saying yu probably have more healing capacity than strictly necessary and could get away with shifting one of them more toward DPS, but there you go.
But shit! I don't have any spreadsheets or disassembly to back any of this up, just my own slightly-more-than-you experience. Also, look forward to Bushi class throwing a wrench in your works and giving you more options .
Ps I love all the LandXYZ jokes in this thread. Keep it up, champs.