Factors that break ghusal

Masturbation

Q:

1. If I masturbate very little and if I think nothing came out, I mean no water came out, do I need to do ghusl or shower?

2. After masturbation, before ghusl, if I want to read surah by mouth (not touching the quran), read zikr and make dua, can I do all of them?

Doubts regarding sperm

Q: I performed my fajr salaah with jammat. After I returned home, I went to take a quick shower before going to university. Last night I can't remember if I saw any thing or ejaculating at night but in the morning while washing between my leg and private organ they was kind of a fluff dirt not on my private they was nothing there. After I smelled my underwear, there was a little smell. Don't know if it was sperm but no sign at all of any najaasat. I just changed my life a week ago after committing a few major sins. By this happening it will make me stop my ibaadat and worship of Allah. I am not sure of what to do. My bedding is not messed. I started my missed salaahs. What do I do?

Discharge

Q: I was sitting and doing nothing. I didn't have any sexual thoughts but some discharge came out. I went to the bathroom and urinated and then I washed 3-4 times. My question is that am I napak because the discharge came out. I wasn't thinking about anything bad? I have been having doubts. If I did become napak but got my periods but I took a shower, will the napaaki leave or will I be napaak and if I sit and use things will they become napak?

Dissecting dead bodies

Q: In medical school you have to take anatomy class and dissect cadavers (dead bodies) for educational purposes of course. The cadavers are non-Muslim as far as I know but you wear gloves and lab coat while dissecting.

1) Do you have to do ghusal every time you have that class because you dissected the cadaver or is wudhu sufficient to do wudhu to pray namaz?

2) If you have more classes after that and you just wash your hands do you have to read anything while washing them?