No, it is not. Just do arena, if you are ready for map 4 enemies it is easy gold farming, and if you aren't then you should stay on map 1.You speak as if every class is capable to have high agility and miss the point that gold farming is a problem in the game.
The problem isn't gold farming, the problem is that it is a bit grindy.
Another problem is the fact that if you go to map 3 and especially map 4 you are basically committed, turning back will only make things worse.
Actually, it might be by design.Again a shortcut, it doesn't address the food shortage at 2-3-4th maps.
The game shouldn't be too easy, or you could just make a VN. There needs to be a challenge.
What challenge author intends this game to have?
And food scarcity is one possible challenge. Though to make it actually challenging the food from inns must be limited. Still, 200-300 food is enough to get to the final boss, if you take food options while you travel.