Definitely no reason to have a total cap on any of these categories. Even HP/MP, Stats, and Others would not be overpowered to give no total category cap.
The one thing I would really like to see though is have it so enmity merits can be toggled on or off. Better yet you could just let us refund limit points for free from +/- enmity.
I would like to see job specific merits possibly expanded too.