Yes. Its fine. License is required only for “developers who work with our library” and it does not restrict you on the number of copies you can distribute “as part of your product”. As long as the “developers” working on it have license, its fine. In case your customers are going to directly work with our library to edit/customize your product, then their developers would require a license too. Otherwise its fine.
Yes. It’ll allow them to work on your product. At the same time it does not allow them to develop other products which are not for your company.
Point 2 of section “Developer License” says “You are allowed to distribute the software along with your product to the end-user.”