Questions about my Harley davidson FXST

Hello, I bought a Harley this year because of an “accident” of my vl 800 suzuki. And now I have to search in here and ask a lot of “dirty” questions, but now you think that some can help me here for sure. Short data Harley davidson FXST First registration 5.1989 The first question is: If I had the goat standing a little longer and then it starts and then let it run and give it some gas in idle, have I always have a relatively large oil stain on the ground on the right, is this normal with this model( a kind of “ventilation” so it has been explained to me, or is it bullshit) photos are in the appendix. Or should I go further on the ground? The black hose goes directly to the motor Second question: I now have a floating disc brakes on the back, which is now so far down that it only clatters while driving, now the question you would install another floating od it is a rigid, in addition to that in the disc also the sensor / magnet for the speed / tacho has been inserted, has the “hole” itself been drilled (which I doubt about the hardness of a brake disc, but you never know ) or are there extra disc brakes that have already made this already? I would also have found a brake disc where I think it could fit, I don’t know if I can link the page here ? I just do it now This brake disc Vielle The third question is My hand brake cylinder is leaking and loses brake fluid which has now nicely “burned” on the white tank I hope I get it polished out. But now the question through all the conversions with steel flex lines and the two disc brakes front etc I am unsure what to buy there for a hand brake cylinder whether there are also any special features there. Yes, I can also in look at the vehicle license, but I have to confess there I won’t be quite smart out of it. I thank you already once in advance for the answers and hope that one or the other has something to pity on the questions:P Greetings