I remember reading patch notes that said Elemental Resistances usually go up with level and now it either doesnt show it the same way or its just removed, so there might be diminishing returns on these things, where it might help alot when theres a lower ammount or lower level but as you go higher its a different story.

As for the Mal Rings themselves, it might have been useful once, but under the current system it might not...i have no clue. Elemental Resistances arent worthless..but how much is too much or just how much +/-10 alone is not that apparent at this point in time..:x At least to me.

Fire does seem to be the most important and most used one however.