Performing salaah or reciting Quraan with a small amount of impurity on one's clothing

Q: If a najaasat-e-ghaleezah that is thin and flowing falls on the body or clothes, it will be excused if the area on which it falls is equal to or less than a fifty cents coin in extent. If the person performs his salaat without washing it off, his salaat will be valid. But to refrain from washing it and to continue offering his salaats in this way is makruh. If it is more than a fifty cents coin, then it will not be excused. Salaat will not be valid if it is not washed off. Beheshwati Zewar (pg 44).

Does this include mazi?

What is meant by makrooh (disliked or sinful)?

Can I still read quran?

Covid positive person attending the musjid

Q:

1. If one is diagnosed with Covid, should he isolate and read his salaah at home, or should he go to the masjid if he is affected mildly (i.e. body strength, very light cough, and fever, minor difficulty in breathing, etc.)?

2. If a person who is Covid positive and goes to the masjid and the other musallis are aware that he is positive, will he then be sinful for inconveniencing Muslim brothers as unfortunately not everyone is comfortable being around the sick these days?