Can the business logic of my website be exploited? [on hold]

I have just finished a website that gives rewards and I'm afraid someone will find a way to use it unwanted and force me or cheat on paying too much. I could use some comments to find out if I missed something that could cost me dearly.

Here is the basic concept:

  • Members can approve others. When you guarantee someone by supporting him, you become one of his "sponsors".
  • When someone works on my site, I bill the employer for the commission I receive, then I reverse part of it as a reward to the "main sponsors" (more information on this that means below).
  • To receive rewards every month, you must work through my site. For contractors, they must charge at least 10 hours per month. Full-time employees must be in their first year of employment.
  • If the sponsor and the person they sponsored occupy one of the positions they found on my website, they receive 0.25% of what the endorsee earns, plus 0.10% of people endorsed and more than 0.05% of them. I did a little calculator on the site so you could see what it would look like:

Here are the protections that I have put in place until now:

  • To prevent someone from sending spam to everyone with endorsements, I have decided that the endorser "accepts" your endorsement.
  • To prevent someone from encouraging a large number of substandard workers to increase their reward, I have established two rules. First, if the person you sponsored receives a negative rating from the employer for a given month, you will not receive any rewards from that endorsee for that month. Second, if you or your signatories receive three negative reviews during a 12-month period, you may not receive any reward for six months from the date of the last negative notice.
  • If, for example, 100 people all approve the same person, I will obviously not pay them all. Only the "main sponsor" is eligible to receive reward points for this customer. Sponsors are initially ranked in order of priority in the order of acceptance of endorsements. If you are the first to sponsor someone, you become the main sponsor and you will remain so unless you do not qualify to receive rewards for a particular month. For example, if you have not charged any time for the month via my site or if you have received negative comments from the employer.
    If you become ineligible, you will not receive reward points for that user for that month and you will no longer be their primary sponsor. You will be placed at the end of the list of sponsors and the next person online will become the main sponsor of this endorsee.
  • To prevent payments from being too time consuming, if you are a contractor, you must complete all your timesheets on the site for the previous month within 7 days of the end of the month in order to remain eligible for points of interest. reward for this month. If you are a full-time employee, this does not matter because the employer is billed the commission immediately, not per month.
  • Invoices submitted to employers must be paid in full before rewards are paid.

Can you think anyway that I could be exploited with this?

Thank you for your help