Well, there's quite a bit of possible abuse lying about everywhere. I just got the golem up to the level he gets the "movement boost" skill. Stay in place, use the skill 5 times for massive experience gain, get a level up (Got a few to catch him up since he was behind nearly 10 levels on my most used chars). Get back 5 energy since you didn't move, repeat for a level up every single turn. Use Emma's Feint skill 20 times in a single turn on a boss unit to get like 5 level ups (in theory, I stopped at 2 levels in order not to ruin my game completely).
I don't think it's "bad" per say that the game offers grinding opportunities. If a player is completely stuck, they are likely to stop playing instead of restarting. Most games nowadays are balanced around the player not grinding, but there's optional stages that a player can do.
There's no optional stages here, no arena, shops are only an occasional occurence, ect. So having the possibility to get some bonus exp (as long as it's optional and not designed as in you need to exploit to win the game) is not a big problem I find (though it makes some units very hard to level compared to others).
