I started out in rallycross but damaged the Jetta I had a little too much. Now I have a Impreza that is in much better condition. I know that in rallyx studded tires put you in the experimental class, is there any limitation on studded tires for road rally?
Also are the rules posted, which are for 2007, the ones that should be read?
Yes, the "2007" version of the NER RoadRally Rules are the current ones. There is an update coming, but it was minor and only affected the wording for the championship points calculations. With regards to studded tires, as long as the tires are legal for use on the roads in the state the event runs in, you can use them on a road rally.
Studded tires in rally-x are allowed in any class as long as snow and/or ice is present (i.e. only at winter events). They must be street legal studs. No ice racing or home made studs/cleats are allowed.