Yes however if you allways move yourr models then you can not import stuff in thet was built in same reference frame, so your models may become incompatible woth each other (assuming they were to start with). Anyway there is some reason the things were modelled of center so they will be there. (ok so most likely the reason is it was done in autodad or something in wich case the origin is allways quite much off since autocad users doent work on origin much)
Besides you dont actually need to know where some model is inorder to snap it to the origin tahst what the middle mouse is for.
As for scale thets easy your using faux meters whereas the 3ds is allomst certainly using meters.