Well I'm only five hours in and it's not bad. I've beaten the games you mentioned on their hardest difficulties in each iteration, and I don't think this one is too bad. Easier than Strange Journey so far, which is what it's closest to for me.
And really there's not much micromanagement so far. I've always had WAY more than enough mag to get through areas. I usually sell most of my mag after completing an area so that I'm left with 1500. From what I understand you're eventually swimming in mag, which means you're swimming in yen as well. Really, don't worry about mag much. Just don't go into a dungeon with almost none, and don't give it all away in hopes of a demon joining you (just to receive a gem instead..). But if you're running low on mag (in the hundreds) and you're mid dungeon, you might lighten your party up a bit if you can handle it. You may also consider using the save-anywhere feature you'll get later in case you need to exit the dungeon and get more mag from the store if necessary. Really, though... you shouldn't end up in such a situation, hopefully.
