Ford Fiesta Flight???

I have a 2001 Ford Fiesta Flight (don't laugh). When I get to 60-70mph there is a n oticeable vibration through the steering column from the engine and it feels like I should not keep at this speed for too long (no good for motorway driving). Also, upon braking from anything above 50mph there is a noticeable "pulsing" to the engine (not the brake pedal) which doesn't instil confidence. Also, when the engine is idle, eg at traffic lights, there is a "dip" in the revs from time to time. Are these things connected and should I be worried? I should point out that at speeds of less than 40mph, everything is fine.