If it's not 1 thing, it's another!

I was going to say check your balancer but, if your smelling rubber this is going to sound wierd but, see if your tail pipes ,where they loop the axle and pass your tires, are rubbing against the tire itself. If not that then go to your brakes someimes a slight brake burn can smell like rubber. I dont know dude good luck that's just where i would start.

does it make vibes or smell while stationary or only while in motion?

Try this to see if you can eliminate some variables. Get up to the vibration point on the freeway (clear traffic), and slip the car into neutral and let the revs drop down. If the vibration continues, it's likely wheel balance, suspension component, driveshaft, u joints, or rear end -- but not engine related.

If it's not engine related, take the car into a good alignment/wheel/tire shop and let them put it up on the rack. They can check for worn suspension components, and they can also check the tires to see if there are any separated belts or anything like that. An internal belt separation can cause huge vibration and/or pulling without looking like much of anything is wrong. If that checks out, I'd have them do a tire rebalance to eliminate that as a possibility. If all that checks out, and you still have the vibration, it's likely driveshaft, ujoints or rear end.

can a balancer go bad, where it allows too many vibes, only at higher revs?

aluminum driveshaft!!! but you missed tha boat on those... so did i