UJM:
1. According to most rishonim, shmitta is meshamet chovos at the end of the year. There are minority opinions that hold the beginning of the year.
2. Financially no. However, as a chizuk for the Takana, some encourage anyway.
3. Needs to be retained until RH. After, if you think that your collection will end up in Bais din and the other party will taana that shmitta was meshamet, you’ll need to prove that it was done.
4. Yes.
5. Yes.
6. Yes.
7. No.