[Gelöst] Hierarchy in translation issue

Background of the issue:
I am working on making WPML function properly for a client, focusing on translating content from Dutch to English and German. The default language is Dutch, and translations have been added using mainly automatic translation. Link to the issue: versteckter Link

Symptoms:
Some of the (WooCommerce) product attributes have not been translated properly (the Dutch words, probably they were translated manually in the beginning. I created a test product with all attributes connected, and submitted that for automatic translation.
The wrongly translated attributes remain untouched.
When I manually edit the translation of a product, and after that resubmit the same product for automatic translation, my manual edit is overwritten.
This is unpractical in this situation, as the default language has some content we do not want to use for any of the translations.

Questions:
1. Why is it that in some cases manual changes to product attributes are not overwritten, while in other cases, manual changes to regular content fields are overwritten?
2. Can you explain the hierarchy in terms of glossary, automatic translation, and manual translation, and the order of these actions?
3. Is it possible to use English, instead of Dutch, as the basis for further automatic translations? What is the status of this feature?