In terms of healing, I've found Great Heal to be a lot more effective than Soothing Dance, though I guess I'll experiment and try and compare them again. I was using Bolstering Dance most of the time prior to the Winter City, but found the party needs to be able to survive taking a lot more damage past this point, and making myself the main healer gives me more freedom with building my party.
Admittedly, I probably would expect Great Heal to have the most healing output, since it's percent-based while Soothing Dance is a flat heal (which is probably a holdover from when resolve was still in the game, where resolve wasn't constantly increasing and SD was a resolve heal). My white mage character has maximized willpower and presence, and will heal 74% of the target's hp with Great Heal, while only healing 120-ish health with Soothing Dance. Brienne, who I'm using as my party's tank, has 403 health, and since the baseline minimum Great Heal can do if you somehow set your spellpower to 0 would be 45%, GH is basically always better than Soothing Dance.
That said, I think a much stronger heal competitor for the charmer is Bolstering Dance. With this high presence and willpower character, it heals roughly 50 health each turn. It's not necessarily going to outheal Great Heal, but it's useful mainly in that it's effectively passive and team-wide. It's somewhat less useful now that threat hard-locks enemy's attacks onto whoever has the highest threat rather than just impacting a chance, but still, enemies may use attacks like cleave or allure, or your damage dealers may accidentally do enough damage to out-threat the tank, and once you're dealing with having multiple injured allies, it becomes more effective. Not only will you constantly be healing everyone, helping in those situations, but you're also not required to spend turns on those heals. If your team got hit by a cleave, to heal everyone with great heal, you need to spend three separate turns on healing (or two if you're a white mage, but you're playing a charmer), while BD lets you spend those three turns dealing damage (mainly teases or other powers). It still won't quite be as effective overall as Great Heal, but it allows for somewhat effective multi-tasking.
With all that said, whether you stick with Great Heal or move to Bolstering Dance, It sounds like your playstyle really wants four stats focused. In that case, I recommend alcohol. Garth sells Monastary Ale for 10 ec, Rose (in KM) sells Dragon's Ale for 30 ec, The Palace of Ice has Winterberry Win, and Rumie will give you Moonshine freely if you've upgraded the Wayfort. All of these things provide a boon which causes your willpower to be maxed out (23 for level 7) for 24 hours. Also, if you've freed and married Kiyoko, and aren't adventuring with her, then sleeping at Kiyoko's house gives a Bento Box once every 3 days, which can be carried and consumed to both maximize everyone's willpower and apply the well-fed buff for the same 24 hour duration. Since both GH and BD scale with spellpower, and many other Charmer powers scale in part or purely based off of spellpower, having a maximized willpower will definitely help you a lot. Plus, you can respec the points you spent on willpower back into whatever stat you didn't invest in before.
I have focussed on increasing my sexiness as much as possible and rely on teasing and Allure most of the time. I mainly want a weapon to use as a plan B against enemies with high tease/pheromone resistances.
If you're not also using some power that scales based on spellpower, and don't want to use one, then try Ashelander. She's a one-handed mace with 40 damage and a sexiness bonus, and unlike the Aphrodisiac whip all of it is not of a type that would have damaged resolve before resolve was removed. Plus she has 20 armor penetration and 10 accuracy, while still being one-handed. She still scales with attack power, so you won't be able to maximize her damage, but she'll still hit decently hard as a weapon.
