I have a ffp account with an airline I've never flown and most likely never will fly, just because they have good earnings on partner airlines that I fly, a very long point validity and even lifetime status cards that are relatively easy to achieve... I might be a valuable person, but oh my, I'm a lousy customer.

Anyway, I would suggest that OP reads and watches the FAQ of EuroBonus as stated on the site. It can be found here: http://www.sas.no/en/eurobonus/about-eurobonus/

Having a specific time-bound window for qualifying for status is common practice with about 99,9% of all airlines, I think. Also, please note that you earn two types of points (as is common with most airlines) : qualification points, which are valid within the time-bound window for reaching status and extra points, which are valid for 5 years and can be used for bonus flights and other goodies.

Can I recommend another program? It depends on your flight behavior. If you fly most with StarAlliance and specifically SAS, then I think EuroBonus is the best choice. I cannot recommend Miles and More, as it's only useful for people who fly a lot in first and business class with the Lufthansa Group nowadays.

Aegean used to be a bargain for people who don't fly a lot but still wanted to make Gold, but the company has significantly changed its program. Asiana still has a good deal, but only when your fly in the more expensive booking classes. Also, United is most valuable when you fly a lot with them, not so much for partner airlines. All other airlines within StarAlliance have relatively tougher requirements than SAS, especially if you don't (often) fly with them.

Also, keep an eye open for special promotions. SAS had an offer about 2 years ago that would give you a gold card for just 2 round trips in Plus, for example.