I never have to add oil to the XX between 6k mile changes and it likes to live in the 9-10k range most of the time. Compare that to my 954 that seemed to always need oil.You have to admit the XX engine is special.
What brand front sprocket did you use? I have never had any play. And yes replace that tire or you will be stressed trying to get back, they go so fast after you hit the bars.