There are two types of commission in the default marketplace: Global Commission:- This is the global commission type applied to all the sellers. Seller Commission:- This is the specific commission type using which the admin can define different commission for different sellers. For more advanced marketplace commission structure, refer Magento2 Advanced Commission Marketplace module. Using this module, the admin can apply commission in six ways.

In the module Magento 2 Marketplace, the store owner can add an unlimited number of sellers and customers.

In the Magento 2 Marketplace extension, the seller can add an unlimited number of products.

Yes, the admin can create customers and sellers for the marketplace.

The admin can reset the password of any customer and seller accounts. The customer will receive a link to reset the password on the registered email address.

The seller itself is a customer, so the seller cannot create customer accounts. Only the admin can create customer accounts.

In the default marketplace, the seller can add various products - Simple, Configurable, Downloadable, Virtual. You can check out the following marketplace add-ons for allowing sellers to create the additional type of product such as - Marketplace Bundle Product Module for Magento 2 Marketplace Grouped Product Module for Magento 2 Marketplace Daily Deals Module for Magento 2 Marketplace Booking and Reservation for Magento 2 Marketplace Event Manager Module for Magento 2 Marketplace Rental System for Magento 2