well, if he got them to fit, then they should work. with that much backspace, the rim goes OVER the UBJ and OTRE. without spacers, my outer tie rod end was within 1/4-1/2" of the rim on my M body, and the zerk of my UBJ is within about 3/8" or so.

no idea on sanctioning body legality, but if you use bolt on adapters made from good material (billet AL, steel), they're just as strong or stronger than the flange coming off you're rear axle, if you use hub-centric "through" spacers with long enough studs, the studs only see tensile load, no bending load, so, as long as the lugs are properly torqued they're safe. heck, A LOT of offroaders use wheel spacers, and some 3/4 and 1 ton truck came with them OEM.