Hi,
First of all welcome to the Tryton forum. Thanks for joining us and sharing with the Tryton community.
Answering your questions: most of what you want to achieve is already implemented in Tryton and what is not it will be easly doable by some customization code. Most challenging part here is to learn who everything is designed and how it works by yourself. So my bigest advice here is to join any service provider to learn the system and get dedicated avices for implemenation. Of course you can do that by yourself but it will be harder.
When facing a production project my first question is always the same:
- Do you on demand production (each sale order is a different product and its components should be decided) or you do fixed production (the products are always the same and their materials is defined before the sale). The first will require some customization for now, the latter is most simple and fully soported by production modules.
We have customers of both cases, even ones that are mixin both aproaches and to be honest we still do not find a solution that works for all cases. Maybe you will be interested on reading On demand production where some of the ideas where discussed.
Having said that I will try to give a list of starting modules (ommiting what have been already answered)
That should be managed by sale_shpiment_cost module
You should have a look at the production modules, which may just be missing the calculation of estimated time of production. There are several solutions to the but probably the best one will be to integrate with a specialized tool like frePPle, as discussed in Production planning My team mate @acaubet did a talk explaining our frepple integration on the Berlin Unconference. Maybe that will be interesting for you.
That is managed by account_credit_limit module and sale_credit_limit modules.
For that you just need to define a tax rule for overseas customers. If you are from a country where an localization module already exist my recomendation is to activate the localization module as it will create the common taxes and tax rules.
Customers and suppliers are managed using the party module
The product module includes the code (which is can be considered as part number) and the sale_product_customer allows to define a specific part number related for the customer
Hope it helps!