Modifying Odoo V12 CE

We run currently a Odoo V12 instance and want to fix issues which are not correct or hindering us. This include: 1. Check and correct the setting of the Odoo´s "Routes and Rules" - We have four Routes in our company: Sale, Buy, MTO and "Manufacturing including outsourcing". For the part of outsourcing we like to add a third party module to be able to create "Manufacturing outsourcing" in V12. alternatively we consider to move to V13, if possible. Also important is that we have three stocks, two of them at subcontractor´s place. 2. Implementation of the correct workflows of above cases and automatisation of them. This need to be tested in an test instance and then implemented into the live system. 3. Creating a better workflow for transport orders - We order an item at a supplier and need to order also the transport from haulier. The Order for both are created automatically from the SO in current state, but the content on the documents is not suitable. That need to be solved more clever and intelligent. 4. Correct setting of the incoming emails in Odoo. The outgoing emails work somehow, but we have problems with the incoming mails. 5. We also want to offer access to a portal for some Clients, including a view on the stock for their dedicated product. 6. We also need to modify the workflow of Vendor Bills and add customised fields into the workflow to enable correct booking. 7. We also need to add some more modified reports such as Product labels, pricelists, etc.. 8. In our seperate instance for our production unit we need to implement complete workflow for manufacturing orders, including manufacturing outsourcing, different stocks and complete reporting in cost and in production. For fullfilling this needs we are looking for an experienced Odoo-Developer or an Agency which is able to jump into it and create solutions without damaging other parts of the program. Means it need to be an integrated approach of a solution. More modifications and customizations are needed in early future. Therefore we are interested in an ongoing Service for maintaining the system, once the project is finished successfully.