I have a credit card from Luxembourg that is somehow set up to ask for signature, even though it can do PIN just fine, and I really don't recommend this setting in Europe, it's a massive pain in the ass since most merchants aren't equipped to deal with that. You end up having to sign the merchant's receipt with a pen like you're back in 1970, it takes a lot more time than entering your PIN (or better yet, contactless without PIN these days).

(And I did complain to their customer service, but they won't change the setting).

Depends on the country, in many EU countries I find chip+sign payments to be way faster than chip+PIN. Every now and then you run into a cashier that gets confused by chip+sign, but not often enough to justify switching back to chip+PIN in my experience.