Recently I had to place these rims from an Infinity on my Accord and due to clearance I had to use spacers so the rims would clear the calapers. Now, the package claims no off-roading and though I don't plan on rock hopping I was wondering if there were an other performace concerns with the use of spacers.
I just don't want a wheel to come flying off due to lack of knowledge.

 

Assuming the spacers are hub centric (match the centerbore of the wheel or you have a centering ring for the wheel), then just be sure the lug hardware is correct; you will need at least 7 full turns of engagement to ensure a safe fit. It wouldn't hurt to check the torque on the lugs a few weeks after install just to make sure all is well.