That was a detailed and thoughtful reply, thanks. I see many of the things I mentioned are just things you are working on. Having a tight inventory is fair at the end of the day, I should've used the stash to store excess potions. Also I wish I found auto-loot, it's really convenient. An idea regarding that; maybe auto-loot potions only of the same level or above to what the player is carrying? Or have a tunable option of some sort. At a certain point I've stopped collecting/using potions that aren't grand. Thing is I've played a bit more since leaving the review and I did use the leveled up spells, since that was the only way left to get higher damage. I ended up investing most of my skill points in in extra mana and mana regen to be able to handle that. Chaining and multiple projectiles are very nice. I can permastun and melt any enemy group now, regardless of size. In the end I leveled to max and have 7 stacks of cash. Here's a brief video showing my situation:
https://files.catbox.moe/i50wdh.webm
Also now that I read the explanation, the mp/sp cost of spells makes sense. A little bit of unintuitiveness is inevitable; people will mess around and find what works, or else browse some wiki for minmaxing like for any other game. So yeah, looking forward to seeing further development!