Thank you! I've decided to drastically scale back my goals for this jam, I overestimated how much work I'd get done each day - and what a difference having the full version of RPGMaker would make. I'm planning to finish a demo or beta version for the jam, then (when RPGMaker goes on sale again, and I can afford it,) develop the game into something closer to my original vision.
And yeah, random battles... can get really tedious really easily. I'm going to include them for the jam, but when I expand the game later, there's going to be a limited (but large) number of individually-designed encounters. The idea was that for most of the ghosts the player runs across in the world, there will be a murderer somewhere as well, and the protagonist's goal is the avenge the deaths of each ghost he meets. The battle encounters wouldn't spawn until the player had talked to the appropriate ghost (that way you're not just slaughtering people willy nilly), and afterwards the ghost would have disappeared (having achieved peace). That way, there'd be a ton of potential battles to level up with, but the player would have to seek them out individually.
It sounds, just thinking about it, very tedious for me to build, but way better for me-the-theoretical-player to play. In theory. Again, for the jam I will use random monster encounters, but I'm gonna see if there's a way I can do them with diminishing encounter rates.