Edits and refinements of the site on Bitrix

There is a site on Bitrix Small Business, quite unconventional (exchange with 1C runs through the intermediate base of the SL). It requires some refinement:
1) Create your own product card for each trade offer
2) Sell related goods in a product card
3) Withdrawal of quantity and date of receipt of goods
4) It is possible to remake the exchange from 1C instead of the base to the API - github.com/yokel13/yapi

I will provide access and address of the site in detail when discussing the task in detail.

In the future, you may still need edits on this or other sites, so please specify in the response how many hours per week you are willing to pay and your bet.