Hi,
1. Payment to the seller is normally not done based on the status of the order. The payment is usually done by you opening the vendor page and clicking the "pay" button in the backend of HikaMarket.
Another alternative is that the payment directly goes from the buyer to the seller. In that case, this happens at the exact moment the customer pays for his order. There is no mechanism to delay this.
For example, with the Stripe connect payment plugin, it's possible for the seller to automatically receive his split of the money on the total amount of the order. The Stripe connect API doesn't have any option as far as I know to delay this and trigger the payment at a later stage.
2. The status of an order can only be changed in the backend. And potentially, you can allow vendors to do it on their orders. However, there is no mechanism to allow customers to change the status of their order themselves.