Peugeot 307 juddering.....please help ('',)

Well,i have a couple of problems.. which i dont know how to even describe to a mechanic!! it is basically i have noticed the car rev counter when im parked/idle with engine on going up and down to '10' at least 5 times, before it settles down. there is also a slight reving noise coming from the engine even though i dont have my foot on any pedals. Also, sometimes when parked e.g in traffic, the whole drivers side, wheel etc feels like its shaking methodically, enen though again no feet on pedals.. Last thing is I find when driving on the motorway, once i go over 110 km, the wheel starts 'convulsing' so much that i slow down so as not to have to control the shaking. this cant be normal!!! any help please?? changing down gears from 2nd to first also very juddery...