I'm wanting a more aggressive stance with my stock 18s. I have a 35x12.5 Nitto M/T. What size should I go with to make my stockers stick out a bit more for a better look and still be safe? 
I agree with RollinPres, I think they do add stress but so do wheels that have less backspacing... My original concern was the same as yours thne I was told it's the same as if I were to buy wheels that would fit, except this gives me the option to go back to OEM offset... Honestly, I wouldn't be running them if my tires had fit on w/o them...
when i had my tires rotated, i had the shop throw mine on for me since they had the wheel off. they acutually said my rims were mounted more safely with them. without them the oem studs were really short and i need something beefier for the large wheel package i had.