Oh oh OH! I'd love to discuss character strategies.
Did anyone actually go for the naked Dunban route? I did, and I put an Agility up gem in one of his weapon slots... it still shocks me how little he gets hit. But when he does, he gets hit hard. I also gave him Topple up gems on his weapon too, since he's honestly the most reliable Topple character in the game.
For Reyn, I have Arts Heal gems out the whazoo on him, along with Spike gems, since he's such a heavy-aggro character. The Arts Heal gems really work because of his excellent Arts cooldown. Finding advanced arts manuals for him is hard as hell, though, and that's the one reason I don't use him more.
Sharla's kind of a weird one for me. She's almost always on my team since she's just such a difficulty cushion, and I've even played as her a lot. If you do, she becomes an insanely good healer instead of just a decent one like she is when the AI is controlling her. While I love Head Shaker and Head Shot, they're so hard to pull off and Head Shot has such a ridiculous cooldown that I sometimes just want to make Sharla a full-on support character. I've considered upping her auto-attack heavily, since it's the only reliable form of attack she really has, but I'm not sure.
Rikki is so confusing to me. I really like the character and I like a lot of his moves, but I'm not sure what I want to do with them. Should I just give him Aggro up like crazy and use Rikki is Angry, which I have maxed out? Or should I keep him as the Debuff whore that I have him as currently? I currently have him inflicting Break, Bleed, Chill, Poison, and Bind before using his Debuff-remove attack, which dishes out 23000 damage, roughly. Which is awesome. But the process of debuffing-and-then-removing has just become boring to me and I want to see if I can do something different with him.
The strange thing about Melia is that I thought I'd really like playing as her, since she's a mage and really does have an interesting play style. But I don't. With the build I currently have, she's next to useless in Chain Attacks, and most of her really heavy hitting moves take so much time to charge because of her elemental discharge. But I do like that her buffs stack, a just wish she had more ability as a healer and more HP herself. I've been considering adding her forced Topple move back into the mix, but I'm not sure.
As for Shulk, I mean... just slap some Arts Stealth on him and/or pair him up with Dunban or Reyn and he's good to go. Backslash does an atrocious amount of damage, and his other moves are pretty reliable. Light Heal is even pretty great for pulling your teammates out of a rough patch when it's maxed out. If I've got him in my party, though, I'm usually using him, just because he's such a perfect setup for Chains, especially Topple chains. I find myself using Aura Seal a lot, and Monado Buster is always nice, though post-Egil, it becomes pretty pointless.

I never use speed, even though it was played up as super important. Shield is sometimes nice, but Enchant is pretty weak. As for Cyclone, it's probably the best of the abilities but you get it so late game that, unless you're looking to finish the late-game quests or outlevel the boss, you'll rarely get to use it. But it forces Topple in droves, which works really really well with Stream Edge. I haven't received the final two Monado arts... yet.
And as for Seven,
she's alright. I don't like how all of her moves lost the exp I gave them at the beginning, but whatever, I guess. I enjoy using her because most of her moves hit so brutally hard, even at lower levels, but I'm not sure what to formulate my battle strategy with. She sometimes even works well as a support with Ether Drain and her other debuffs but I'm still not sure what role I want her to fit. The Xenoblade Wiki suggests a tank build for her which I'd be interested to try, if only because it would let me do some other interesting things with the other partners.