Do not introduce Business class on intra-european flights. Plus is fair enough and very valuable for short flights and have a human price (like Norwegian and Ryanair).

Make a “code-share” cooperation with train providers, to allow for booking a ticket from A to B with combined train-plane modality and same benefits as connecting flight

More variation in aircraft sizes = optimized cabin factor = less fuel consumption/passenger

Include a minimum of 50% bio-fuel for all SAS Business seats. Market it as a part of business being reintroduced in Europe. A win-win, for both customers and airline.

Just one sickbag on each row, kept in the middle seat.

Mount small blades on the side of the wheels to make them spin by themselves before landing to reduce tyre wear upon contact with tarmac.