1) First: Witch Swap
I definitely want to make this mechanic more useful. I think making it so it removes both buffs and debuffs could be interesting... It does give you a small heal currently, I could also increase that value. I'll keep thinking about it! ^^
2) Next one on the list: Cards (rebalances/reworks/new cards)
Balance still needs a lot of work for sure! There won't be as many spells available this early in the final game, their availablity and some of their stats will be rethought. Some spells will have evolved versions as well, and I do want a lot more variety and weird effects in the future too! I'll do my best :B
Also, the reason Nightmare didn't take damage from Earthquake is because she nullifies all yellow damage she receives ^^
3) Monstergirls's Unique Abilities.
No worries, they'll each have a unique skill in time! ^^
In Cerelea's case, I want hers to be Wall smasher, the same spell she uses when you face her. The more stone blocks destroyed, the more damage it deals
4) Reviving witches
That's completely fair! I've included a bunch of monstergirls to be revived, but there won't actually be this many this early in the final game. I'm also thinking about some way to make it easier to meet her as you said, which will help a lot ^^
5) Sidequests
This is indeed the very first (and currently, the only) quest in BEW! I know exactly what you mean. For the most part, I plan for most sidequests to relate to one or several playable characters. They'll be optional, but double as a way to learn more about the characters. They'll give some good rewards and in some cases be a criteria to rank up said characters. I have a bunch of ideas when it comes to this (including relating to Cha!), so no worries there, I'm confident! ^^
6) Cute little in-game details.
I love these little seemingly pointless things, so you can definnitely expect more of that too ^^
There will also be more party events that trigger as you explore under certain conditions. This is a very recent system so there are only a few non optional ones currently, but there'll be more!
7) Secrets and Rewards from them
Agreed! For now, I chose to make it so you only need 10 power orbs to rank up everyone, so you don't need to find all of them. In the future, quests or more obvious puzzles will be how you often most of them. The golden tree will have to do with a quest as well, so it won't stay this hard to find.
No worries, I really appreciate that you took the time to express all this! It will only help me make the game better ^^
A lot of these issues are due to the game being a WIP and "early" balance. I agree with pretty much everything you said and in most cases I have some sort of plan in mind, though it will be some time before I can implement it all. I'll get to it at some point, for sure!
nosebecc@gmail.com is an easy way to contact me, I guess I wouldn't mind sharing my discord handle there. I need to mention that I've been especially busy of late however, so even though I do my best to get back to everyone, it might take some time!