For items, I was thinking that you could implement a scaling effect system for a certain level of damage reached. For example, if a character has 100 slashing damage, they get 10% more slashing damage. Same goes with health and luck, speed, etc.
For races, you don't have a race that's immune to lightning, and none of the physicals (although please keep it no physical.) You could create a new race that has something to do with rubber or another non-conductive material.
Also, in what country do you live, just so I can know time differential and when to expect a response. Because I live in the west coast of the U.S.