pickd it up today, problems already!!!!

well as it says picked up the maverick today, 30 mins later on the way home, BANG!!!!! goes the gearbox breather, take it back, and just make it and they clean the breather out top up the gearbox and away we go again,

NOT A GOOD START IM THINKING!!!!!

thats been fine since, done 100miles after and all seems fine,BUT,

at tick over it idles a bit rough, bit like a taxi, although as you pick speed up it clears, any ideas????

and also apparently the drivers side has a dry joint that just needs greasing? is that ok or should it need a new joint?

happy enough with it still just want to sort this tickover problem out, its had new plugs, leads, cap and rotor so im thinking crap in the jets maybe?
suggestions anyone?

thanks again for looking and reading, i do apprieciate it and thanks for any tips,
all the best,
craig