Assalamualikum. I follows Shafii Madhhab, hope that your answer also will be in Shafii Madhhab.
1: sometime after I make istinja a very tiny drop is seen at the tip of penis, sometimes I feel that something is dripping but I cant see any drop but sometime I see a drop on penis which doesnot flow (because it is very tiny) and also I check my underwear but I cant get any bad smell what will I do, because of this I am afraid to urinate and I only urinate 3 times a day and I am afraid if I get any disease Please help me what will I do?
2: I have a doubt that floor and walls of my bathroom is impure.I dont know if there is already impurity existing or it will be my doubts because of my waswaas but my parents are not bothered about it ,they make ablution and walk through that floor and go for namaz. What will I do, I think should I ignore it. Can I ignore these thoughts?
3: while making istinja on standing bowls(toilet at shopping mall , college ) some drops are scattered to my pants and shoes if they are impure can I make namaz with that pant.