You have to start somewhere and i opened discussion with my topic about removing immunities where people could get into that deeper how to do it.
I could of course suggest many other changes how to compeltely balance the game, changes connected to immunities, but I didnt want to scare people too much with multiple changes at once as people go into crazy mode just because you suggest one change.
Idk if you saw my topic My dream version of D2R ( I am actualy creating it with modding)
I actualy do changes like that there and if you check the all patch noted i keep posting there, you will get some idea how i balance the game.
I am currently doing testing playrun on sorc for purpose of balancing. What I did was removing immunities and all 3 sorc masteries are set at
at level 1, every other level adds -5% and +5% to dmg and to -enemy res. I will do test runs with testing all skills at several level brackets and balance dmg of skill accordingly so nothing is too weak or too strong, or maybe tweak mastery even more.
Other characters will have various ways how to deal with high resistant monsters also, For example Holy fire, Holy shock and Holy freeze have -enemy resist to their element based on hard points in auras.