You are correct, credit card transactions are about 18% by number and 25% by value.

https://www.riksbank.se/en-gb/statistics/payments-notes-and-...

(Seriously, people, these kind of statistics are extremely easy to find. No need to make them up!)

I have a DC and cc from the same bank.. not sure if it gives much of any redundancy, but it was the best deal on a cc I could find.

In Sweden, the best CC deals are the petrol station branded CCs (Shell/Circle K) as they both give you cash backs, have some insurance, have the standard grace period, and are "free".