0. Thank you!
1. It's more a balancing thing for the game in development. Once the game's finished I might remove that restriction. As of now, I don't want people to min-max the fun out of the game by grinding. If I gave people the option to grind out all the rewards in Mistral Village right now by just sleeping over and over about 50 times, some lunatic might actually do it.
2. That's a pretty good idea. I'm introducing a repeatable quest in the next update too. People have made it clear they want some form of repeatable content, even if it means they overlevel.
3. Esuna is more to be used to counter multiple ailments simultaneously, otherwise you could just use an antidote. However, there is no item bar a remedy that can cure a silenced, sleeping and poisoned individual for instance.
0. No prob!
1+2. Yeah, that makes sense. A little leeway for people to play the game in different ways isn't necessarily a bad thing-- allow some forms of grinding for the people who get a dopamine shot from watching numbers go up, while maintaining the value I presume is important to you, which I gather is 'grinding is never necessary for progress; all content is possible to clear with the resources and tools the game gives you'.
2 1/2. Another possible quality-of-life thing could be streamlining the process of collecting resources from the farm/mine/fishery/shop. It's a lot of menuing to perform, and there's a penalty for forgetting too long. Getting all the resources sent to a little chest icon on the village map? Cutting out the complexity and dropping the goods right into your inventory via delivery when a new batch becomes available?
3. My philosophy on this kind of stuff is, the reason that Life spells are costly is because death is avoidable, and to incentivize you to avoid having to use Life spells regularly. It makes sense for it to be cheaper to heal your party before they die than to bring them back up afterwards; unless you're in over your head, usually you aren't gonna die if you're keeping up with your heals. By contrast, unless you have the foresight to dedicate your gear to status effect resistance (and sometimes even then), if you're facing something like pumpkins or wasps that spam poison attacks, you can very quickly find your whole party poisoned, and it's far less avoidable than taking a death usually is. Your point about it healing
all status effects is well-taken; however, that's the only status heal move you get (at level 11, too), and sometimes I'd rather spend MP than money on healing, much like sometimes I'd rather cast cure than use a potion. Keeping Esuna expensive and adding a cheaper, earlier Purify spell specifically for poison (because that one lingers after battle) could be a nice compromise.