If you are struggling just with the hills, you can get the gearing changed by lowering the whole gear box (my completely non technical term). I haven't ridden the Linus mixte. I have a mixte with the 8sp Alfine hub. During the build I prioritized getting a low low gear to deal with hills. And the lower low helped a lot. Until I hurt my knee this spring. So I am debating if I want to get an even lower low gear. But it is an easy change for the bike shop.
Also, see if you can find a bike shop that specializes in townie bikes like the Linus. There is a shop near my house that only sells urban utility bikes. Linus. Custom builds with steel frames and fenders etc. They love this type of bike and totally understand wanting to replace my rear rack with a nicer looking one. The stock porteur racks and everyone's bike, whether new or vintage is practical. No weight snobs at this shop. It is a great place to get advice and my work done.
Now I have switched to a tricked out soma mixte set up at as a perfect townie bike. We have enough urban commuter shops where the reaction to my bike is positive. Even the mechanics are excited! "Omg, you have the Alfine hub! Dynamo lights, I am going to add those too. Nice fenders."
Find a better shop.
