Re: spacers on front only
If the shop did it and told you it would be fine then you "should" be able to blame them if anything were to happen. Will it hurt anything its doubtful. Would I do it to my jeep. Probably not. I would want to make it match or chage wheels. But I'm also OCD about things like that. I'd notice the width difference every time I look at it.
Rear my sticky thread on wheel spacers at the top of the off road modifications section.
-Kyle '05 Dark Khaki (PJT) WK Limited 4.7L V8, '08 Overland Front End, Custom Exhaust, 245/70/17 GY Silent Armors, Bilstein 4600s, K40 Calibre DL Radar Detector/Laser Diffuser, CB.
Wife's Jeep: '06 Jeep Liberty KJ 4x4 2.8L CRD Diesel