Due to different suppliers and delivery conditions, there may be price differences compared to other suppliers. We always try to offer a price in line with the market. However, this is not possible for all products.
This is a question I would ask the customer service department where I bought the Bose from, they would know best if there are spare parts or if you can only buy the Bose as a whole.
Unfortunately, we can't answer this question for you, as we haven't been able to try this out in such a form, but I'll be happy to enter it in the community, perhaps a user can help you :)
The charging case is included in the scope of delivery.
I hope I was able to answer your question. If so, please accept my answer as an answer to your question.
I am sure the customer service can give you more concrete information than other customers here in the community. See also: https://www.digitec.ch/de/Wiki/4490
That's a matter of taste. I don't like it either, but I have good sound and freedom of movement. B&O H8 are slightly smaller but the sound is better with Bose. Both take a long time to charge and that's that and size are the only drawbacks. Best sound is the Bose soundsport wireless model. It has the best sound but both in ear headphones are connected with a cable.
Unfortunately, we can not do anything for you here. However, you can ask the manufacturer, if you get a support there or ask your household contents insurance, if a loss is covered.