After I had prayed, I found a drop of menstrual blood and was unsure when that happened; what is the ruling on my prayer and fast?
All praise is due to Allah, peace and blessing be upon the Messenger of Allah.
Your prayer and fast are correct ,and you should not make up for them, and we ask Allah, The Almighty, to duely reward you for these acts of worship. Your menses start once you see blood because the situation remains as such unless there is certainty or predominant conjecture, as per the Fiqh maxim: "Certainty is not removed by doubt". And Allah Knows Best.
Is my husband entitled to take my salary?
Your salary is yours, and you may give some of it to him as a kind of free-will contribution.
Should missed Sunnah prayer be made up?
Making up missed voluntary acts of worship is from Sunnah.
I joined a savings club and was scheduled to receive the payout first. My friend asked to take my place in line, so I requested 50 dinars in exchange for letting her have my turn. What is the ruling on this?
This is impermissible, as it involves taking money without providing something of value in return according to Islamic law. And Allah The Almighty Knows Best.