The way i see it is if you outlaw the single trucks from running duals to gain extra traction when needed, then you are going to hafta outlaw the dually trucks, then that nixes alot of guys from pulling that happen to have 3500 trucks. I can see you adding a rule that requires the tires to be covered but then that would also require guys with wide fronts to be running some kinda flare.
As far as driving versus pulling, Most of the guys that pull in the street that i know can drive thier trucks whenever they want. However i would say most of them also have a spare vehicle to serve duty as a tow rig, because who wants to drive 300 miles from home to a pull and break and then try to get home? That tow rig often times finds itself as a parts getter and daily driver when the other truck breaks, and i know for one my tow rig is alot nicer then my pulling truck (not alot of guys go hacking on thier new truck, except Dmax boys :--) ) anyways you start to drive the tow rig more.
The Green machine has had 1250 miles on it since the last test clutch was installed in late august, Most of the winter it sat in the barn , because of some other little things we were working on, and the fact that it is hard to safely drive 500 hp in the ice pulling a bobcat trailer. It has more recnetly seen alot of miles on sunday afternoon going to get a snow cone :-laf
AS far as RPM limit goes thier were a few trucks that were boarder line/or over the 4500 rpm limit, I know our green dodge was right thier (4500 rpm is the rule so you better belive it is going to run 4490rpm) Kinda reminds me of someone measuring Justin Burns (Lifted dmax) weight bracket, Somebody commented man that is close, Justin comment 59 and 7/8

. I do know that thier is ways to check RPM and that may be an option in the future, and i also know that at least one competitor was warned.
Also remember if you want to make a street class (stock charger only) it will be dominated by Dmax's those little boogers can pop off a 500hp run on the stock charger
Travis